Brief History Of Thyroid Tests And Medicines
It has long been known that thyroid hormone deficiency can lead to severe physical impairment and even death. Recognition of the signs and symptoms of deficient thyroid hormone in subtle cases was first made possible by experience that was gained in the more severe cases. Severe thyroid hormone deficiency is called myxedema or myxedematous coma. It was called this because in severe cases of thyroid hormone deficiency patients become edematous or severely swollen, they can have decreased levels of consciousness and can even fall into a coma.

It wasn't many decades ago that doctors first began to understand the significance of the thyroid system. Patients would sometimes develop dry, coarse skin, slowed reflexes, hair loss, brittle nails, thinning of the lateral one-third of the eyebrows, thick swollen tongues and other severe complaints. When these patients were identified early enough and treated properly with thyroid hormone supplementation, their rapid and dramatic response to thyroid hormone supplementation was extremely gratifying. As the patients gradually improved, doctors were able to become familiar with the varying degrees and effects of thyroid hormone deficiency.

In time, a test was devised known as the Basal Metabolic Rate Test or BMR Test, which was intended to help identify patients suffering from thyroid hormone deficiency. The test consisted of the patient waking up in the morning, remaining motionless, and breathing into an oxygen mask with the doctor measuring the amount of oxygen consumed by the patient in a given period of time. With the amount of oxygen consumed, the doctor could calculate the patient's Basal Metabolic Rate and compare it to the Basal Metabolic Rate of other people both normal and ill to help determine whether or not the patient might benefit from thyroid hormone supplementation. The test was cumbersome to perform and therefore was often done improperly, which added to its inaccuracy.

The BMR test did not have as much predictive value as was hoped for. Later a protein bound iodine (PBI) test was developed. It was felt that the level of protein bound iodine in the blood should somehow be closely proportional to the level of the thyroid system function in the body (which is not always the case).

Then tests were developed for T4 and T3 specifically. These tests still do not have the predictive value that would be preferable in the treatment of decreased thyroid system function and the consequent symptoms of MED.

Since then, a myriad of other tests have been devised in an attempt to find a more reliable test, one of greater predictive value, in the treatment of patients suffering from symptoms of thyroid system deficiency.

One test known as the Radioactive Iodine Uptake test involves radioactive iodine being ingested by the patient and taken up by the thyroid gland which is then scanned with a radioactivity scanner to detect the level and pattern of radioactive iodine in the thyroid gland in an attempt to get an idea about the thyroid gland's function. There is the Thyroid Stimulating Hormone test, Thyrotropin Releasing Hormone, T3 uptake, T4 index, T3 index, T7, RT3, and others. These tests have their uses and are directed at assessing various levels of the thyroid system but are not extremely useful in predicting the onset and/or resolution of the symptoms of decreased thyroid system function. It should be pointed out that some of the thyroid tests available are actually measurements that have been mathematically manipulated in an attempt to increase their usefulness - without much success.

Medicines Used
In the beginning, patients were given thyroid hormone supplementation in the form of desiccated (dried out) animal thyroid gland tissue and patients are still treated today with thyroid hormones that have been purified and extracted from animal sources. Later, synthetic sources of thyroxin (T4) and liothyronine (T3) were developed. These medicines have been on the market for decades. Currently, synthetic sources of thyroid hormones are often considered better because of the greater consistency from pill to pill.

Inherited Attitudes Of Doctors
Let us explore, briefly, the attitudes that doctors may have had over the years. Early in medicine, a doctor may have been able to be well-versed with all the available medical information, and he might have felt comfortable in having mastered a certain body of information. When teaching the next generations of doctors he might have said confidently that he was teaching the young physicians everything that they needed to know about a particular field. Those young physicians may have believed it, and they may have admired their professor and tried to emulate him by trying diligently to study the expanding medical information and to master it. As they taught the next group of physicians, they too may have passed on the notion that they were being taught everything that there was to know. For what other purpose does a doctor attend medical school? I think this pattern may have repeated itself over the years. Believe it or not, even in my medical training, which was not many years ago, on more than one occasion did a professor or an attending physician imply, if not come right out and say, that we were being taught everything important that there is to know. Unfortunately, those who believe that they are being taught everything, tend to stop looking for anything else. Thankfully, there were some professors and doctors who admitted that it was impossible for any doctor to know everything, and they emphasized more fully in their teaching the importance of being able to evaluate the available medical information and apply that information with proper problem solving techniques in the treatment of patients' problems. It is always amazing when any doctor seems to be able to muster the confidence to think for a moment that his medical knowledge is exhaustive, and therefore that his opinions are necessarily correct.

We all know that many times the things that we assume to be true aren't even close to being true or correct. In fact, it is often surprising how far off base some of our assumptions can be. As we discussed earlier, it was assumed that because the earth seemed flat, that it was flat.

All these factors have led to surprising assumptions, surprising attitudes, and surprising conclusions regarding decreased thyroid system function, its treatment, and the patients who suffer from it. For example, because DTSF can cause certain symptoms and can sometimes lead to death, doesn't necessarily mean that a treatment that prevents death sufficiently corrects the symptoms. And because severe symptoms could be, in the beginning, correlated to diseased thyroid glands, doesn't mean that they were caused only by diseased thyroid glands. Diseased pituitary glands were later discovered to be able to cause severe symptoms, even with normal thyroids, and it was seen that the previous assumption was incorrect. However, because diseased pituitary and thyroid glands can cause severe symptoms, again, does not mean that they are caused only by them.

Another assumption is that since patients that have excessive thyroid hormone activity in their bodies sometimes exhibit nervousness, fatigue or headache, that therefore, anyone on supplemental thyroid hormone treatment who exhibits these symptoms is necessarily on excessive amounts of thyroid hormone medication. This is in spite of the fact that decreased thyroid system function can also cause symptoms of nervousness, headaches, and fatigue.

Throughout history, we have seen how wrong and sometimes silly assumptions can be when based on a limited perspective. This points out the wisdom of a principle that a doctor once taught me. He pointed out the distinction between people who are sick and people who are ill. People who are ill, are uncomfortable or unhappy for some reason, and feel that they have something wrong with them for which they may seek help. He pointed out that people who are ill may also be sick, meaning that they have some physical problem that can be shown to be the source of their complaints or illness. He went on to say that there are some doctors who only treat patients who are sick. When it is determined that the patient does not have an easily identifiable physical problem, then they may feel that the patient does not need help and completely overlook his illness. Better doctors, he said, address themselves to patients' illnesses by trying first to find a sickness that is causing their illness. But when and if they are unable to find any sickness, they, nevertheless, endeavor to address the patient's illness by acknowledging it and by endeavoring to help them deal with it as well as possible.

I believe that the doctor was trying to teach the importance of compassion, empathy and being supportive. But I see additional wisdom in this principle, because it points out that people who are sick are people who have physical conditions that can be diagnosed and detected using available medical technology.

But, what if a patient's illness is being caused by a physical problem that is not yet easily detected by available medical technology, and what if a patient is told that he or she does not have a physical problem, when in fact, he or she does? So, to me, the principle emphasizes and helps one to remember an extremely critical fact that all physicians and patients should always be aware of. That fact is, that current medical science is not exhaustive, and just because someone is suffering from a condition that cannot be easily identified or treated, at this time, doesn't mean that the person does not have a physical problem that may even be severe, and that could be treated if our understanding was more complete.

Where We Are
Unfortunately, in spite of the development of the many and varied testing approaches for the thyroid system and the various thyroid hormone medicines available on the market, doctors still have been unable to find a very predictable method for relieving the symptoms of decreased thyroid system function, particularly not through the use of thyroid blood tests as a guide. There are many patients who, after developing symptoms of decreased thyroid system function, enjoy improvement of their symptoms of thyroid hormone supplementation to the satisfying of thyroid blood test criteria (returning of the thyroid blood test values back once again within the normal ranges), without enjoying anything close to a complete resolution of their symptoms to pre-illness levels.
 

As I look back on the lectures that we were given on the thyroid hormones and the thyroid hormone system in medical school, I can remember the general consensus among the students being that the lectures on thyroid hormone physiology were among the most confusing lectures in medical school. There was a complete review of all available thyroid hormone testing procedures and how the values of these tests would change under various conditions. Some of this information was comprehensible, especially the part relating to the expected thyroid hormone level changes found in the different glandular abnormalities of the thyroid system. For example, learning the changes in the levels of T4, T3, TSH, and TRH, in primary and secondary hypopituitarism, hyperpituitarism, hypothyroidism, and hyperthyroidism. However, much of the other material presented was considered by the students to be quite confusing.

I will present at this time, very briefly, some of the information that was incomprehensible. Note to the reader: If you find this information confusing and hard to understand, don't feel badly. Doctors do too. Just quiz a few. Even doctors who do understand it, usually can't use it to best resolve the symptoms of DTSF in the most effective and predictable manner. "Even when clinicians suspect hypothyroidism [one cause of DTSF], correctly interpreting thyroid function tests is a difficult challenge. For example, a reliable means of directly measuring serum thyroxin (T4) is still not routinely available. And indirect measures of estimating free T4 are prone to misinterpretation...." (Overcoming Diagnostic and Therapeutic Obstacles in Hypothyroidism, Emergency Medicine Reports; Vol. II, Number 23, November 5, 1990).

We often try to "guesstimate" how much T4 is floating freely in the bloodstream (as if knowing that amount exactly would necessarily permit an adequate evaluation of thyroid system function!). We do this by measuring the total T4 in the blood. But we know that the results of this test can be affected by the level of Thyroid Binding Globulin or TBG (the globulin to which T4 is often bound in the bloodstream). Increased TBG levels can display decreased T4 levels. TBG levels can be increased in pregnancy, the new-born state, birth control use, and other conditions.

TBG concentrations can be decreased when male steroids are used, cortisone is used, there is chronic liver disease, there is other severe illnesses, and under other conditions. One can see how the interpretation of a T4 test would be difficult because of the effect of TBG.

A test was devised, called the T3 resin uptake (T3RU) test, in an attempt to help one estimate the effect of TBG on the value of the T4 test to help one better "guesstimate" how much T4 is floating freely in the bloodstream (even though knowing this amount exactly still would not necessarily correlate with thyroid system function). These preceding tests are not even considered to very adequately reflect thyroid gland function, much less system function. For this reason, thyroid stimulating hormone is considered to be a more sensitive indicator of thyroid gland function (which many mistakenly equate to thyroid system function).

Since the purpose of the glands is to secrete hormones into the bloodstream as influenced by the levels of other hormones present, measurements of the levels of these hormones can well reflect the function of the glands (thyroid gland, pituitary gland, and hypothalamus). The function of these glands is quite important in maintaining adequate available levels of the raw material, T4, in the bloodstream. However, T4 is not the physiologically active thyroid hormone. T3 is the physiologically active thyroid hormone. Most of T3 is produced from the peripheral conversion of T4. It is called peripheral because it takes place outside any gland.

Knowing What We Don't Know
Many people (even doctors) mistakenly assume that doctors know everything, and that if a doctor doesn't know everything, then he should know everything, because everything is known.

However, medicine is far less of an exact science than some people make it out to be. If it were exact, doctors could fix 100% of the people 100% of the time. It must be remembered that not everything that is written in the medical literature is correct. We have often seen how opinions in medicine can vary tremendously, even in a short number of years. For example, most people are aware of the controversy surrounding female hormones. In the beginning, it was suggested that they should be taken to prevent symptoms, then it was feared that they should not be taken due to an increased risk of cancer. Then it was recommended, again, that they should be taken to prevent osteoporosis, and still the controversy continues. The same can be said about the amount of fiber in a person's diet. We have seen wide shifts in recommendations from the medical community. First, fiber should be taken in the diet, then a person should eat no fiber in the diet, and then again that they should eat fiber, etc.

While I was in medical school, I heard it said that if one doctor were to read everything that was printed in the field of medicine in the year of 1978 alone, that it would take 54 centuries to read. Of course, since the year of 1978, the situation has grown far more formidable. So, of course, it would be impossible for a doctor to absorb, comprehend, and analyze even a fraction of the available information in an entire lifetime, much less within four years, or twelve years, or even twenty years of medical training and practice. Nevertheless, there are some unfortunate doctors who seem to suffer from the misconception that they do know everything that there is to know about the human body in any of its areas.

Considering that the entire mass of information cannot be comprehended at one time by any human mind, it seems that it would be difficult for any person to determine which, of all that information, is the most significant and what parts of that vast amount of information should be taught in medical school. And even if it were possible, doctors don't always agree on what is most significant. That's what second opinions are for. The things that are taught in medical school are extremely small portions of the available medical information, almost like needles removed from the haystack. It may lead one to wonder how it is being determined what needles are the most significant and what needles are not.

It is understandable that the information pertaining to some conditions (especially those that are life-threatening) have gotten more attention than others. But that's unfortunate for people who happen to be suffering from other conditions. Because, even though their condition may not be life-threatening, they can feel so miserable that they sometimes say that they "would have to die to feel better." It should be remembered that simply because symptoms are not life-threatening does not necessarily mean that they are mild, or not severe.

Our Technology Only Reaches So Far
It probably should be pointed out at this time why there are some things that are easier to document and test than others. The human body is extremely complex in design. It is a highly organized system and it is organized in various levels. The organism is made up of systems. The systems are made up of organs. The organs are made up of tissues and the tissues are made up of cells. The cells are made up of subcellular organelles which are made up of molecules. Molecules are also involved in the chemical reactions.

In general, the higher the level or organization wherein lies the problem, the more specific and documentable the complaint. The lower the level of organization wherein lies the problem, the more generalized and the more difficult to document the complaint. For example, the highest level of organization is the organism taken as a whole. It is easy to see whether or not an organism is alive or dead. When one goes down to the next level of organization of the body, the systems, it is also not difficult to recognize the problem. For example, if someone suddenly pushed himself away from a steak dinner clutching his throat, turned blue in the face and fainted, it would not be hard to see his problem as being respiratory. Neither is it difficult to recognize when someone has a digestive system problem when they vomit everything they eat, and when they stop having bowel movements.

Things are a little less obvious when one goes down to the level or organization of the body represented by the organs. Nevertheless, certain groups of signs and symptoms are usually easy to recognize as being related to a particular organ. For example, not being able to move the left side of one's body is consistent with having a stroke in a particular part of the right side of the brain. Severe pain in the right lower quadrant of the abdomen coupled with significantly elevated body temperature often leads one to think of appendicitis or inflammation of the appendix. Shortness of breath and wheezing often leads one to think of asthma

The problems that are related to the next lower level of organization of the body, namely the tissues, are even more difficult to recognize. Problems at this level are somewhat harder to identify and frequently require the technology that is available through various tests to help identify them. For example, different problems at the level of organization of the tissues can cause fatigue. It is known that patients with liver problems, kidney problems, anemia, and even thyroid gland problems can develop fatigue. Blood tests, urine tests, x-rays, and scans can often help us to determine the source.

The even lower levels or organization, such as the function of cells and the chemical reactions among the molecules, are among the most fundamental processes of life. Symptoms that result from problems lying at these levels are that much more difficult to document. Yet that does not mean that they don't exist. It only means that we have not yet been able to devise tests that can reproducibly and predictively evaluate certain problems and their symptoms. For example, the symptom of depression can be caused by a number of things such as chemical imbalances in the brain that can result from various chemical processes resulting from various causes such as abnormal production or breakdown of neurotransmitters, imbalances brought on by stress, and imbalances that result from substance abuse. It is extremely difficult to measure the levels of neurotransmitters, and the functioning of the cells and chemical reactions within the brain to determine the exact cause of a patient's depression. Nevertheless, that does not prevent depression from being recognized as a debilitating symptom that often responds well to treatment. And it does not prevent antidepressants from being some of the most widely prescribed medicines in the world.

It is understandable that more easily documented and observed processes should be given a lot of attention by medical science. But some of the more fundamental processes of the body are extremely important also, even if they cannot be easily monitored or measured. Is it any wonder that some of the more fundamental processes of the body have not gained as much attention from the medical profession as other more easily documentable problems? (It is commonly joked, for example, that doctors don't know much about nutrition.) It should be remembered though, that just because things are not easily documentable or measurable doesn't necessarily mean that they are not important or that they do not exist.

The assumptions that are made and the theories that are formulated to describe things that aren't easily documented are worth looking at. However, just because people were not able to see that the earth was round, didn't necessarily mean that it was flat. In fact, there are still many things in medicine that have been difficult to document and measure, but we don't have to jump to conclusions.
 

It is interesting how much stock people are willing to place in blood tests and any other kind of test for that matter. It must be remembered that computers only do that which humans program them to do. Likewise, the significance of certain statistics depends on who's interpreting them and the usefulness of tests also depends upon how they are being interpreted. It is interesting that we (possibly because of our perception of our medical technology) are easily convinced by the results of almost any scientific tests. Let me take a moment now to put tests into a little perspective. Contrary to popular thinking that tells us that blood tests, x-rays, or other kinds of tests are always conclusive, they are more frequently than not equivocal and non-conclusive.

Nevertheless, with our increased reliance on technology, frequently people are led to believe that these tests are extremely conclusive. Somehow this might be brought about by the notion that if a machine costs $600,000 or $700,000 and it can measure intricately the vacillations of the electron clouds of the tissues of the body or something equally amazing and mind boggling, then the results must necessarily be conclusive and useful in all situations, which is, of course, not always the case.

One must realize that tests are not 100% accurate. When one uses a test to determine whether or not someone has a disease, the test sometimes will be positive and sometimes negative. When a test is positive and the test is correct, then that is called a true positive. When the test is positive and the test is incorrect, it is a false positive. When the test is negative and it is correct, then it is a true negative. When the test is negative and the test is incorrect, then it is a false negative. One must remember when choosing a test one is attempting to find a test that has few false positives and few false negatives. In medicine there isn't anything that is exact or 100%. The fewer false negatives and the fewer false positives a test has, the more reliable and the more useful it is.

Normal Range
A few comments should be addressed to the "normal range," since so many people are often dismissed as having no physical abnormality on the basis of their blood tests being within the "normal range." When they do have a physical abnormality that doesn't show up on a particular test looking for a particular problem then this is what is known as a false negative. It must be remembered that the "normal range" is an arbitrary setting of upper and lower limits in order to establish who does and who does not have a problem. As everyone well knows, what is normal for one person is not necessarily normal for another. Everyone is different. Some people are low, some people are a little higher, and some are higher still. If one plots the number of people having a certain value against the possible values that the tests can give, one finds that in almost any type of medical test, the distribution will follow what is known as a "Bell Curve". It is called this because it is shaped like a bell. Most people will tend to have similar values (representing the middle of the distribution). With fewer people having extremely low or extremely high values, the curve takes on a bell shape.

Let's suppose there are three groups of people. Group A are people who have a physical abnormality that causes their values to run below normal, on average. Let's suppose that Group B is a group of persons who are not sick with an illness with which this particular test correlates. Group C are people who are sick with an illness that causes the values of this particular test to be above normal, on average. By looking at the first shaded area, we can see that some people who are normal have values that are actually more typical of those who have an illness that causes low values. In the second shaded area, we can see that there are some people who are sick that have values that are very much at a level that would be consistent with a normal person. In section three we can see that some of the people who are sick with a sickness that can cause high values also have levels that are more consistent with people who are without illness. In section four we can see that there are some people who are without sickness, who have values that are typical for people who have a sickness that causes elevated levels, on average. So this diagram points out what everyone already knows, and that is: what is normal for one person is not necessarily normal for another.

Without getting too deep into statistics, I would like to point out some common sense reasoning as it relates to "ranges of normal."

The Bell Curve shape has a curved central portion with tails on either side.

These bell curves can be of different shapes for different tests. Some may be broad and some may be narrow. Broad central portions indicate that the observations obtained have a greater degree of variation in different people, and narrow ranges of normal indicate that the test value of each person tends to be much more similar to the values of other people.

As we discussed earlier, entropy is the nature of all things to go toward disorder. If there is no influence causing things to be otherwise, things naturally tend to be random. Tests that have random results form a curve shaped like a rectangle as seen at the top of the following diagram. There is no influence that is causing any one particular value to be found any more commonly than any other possible value. This causes the curve to take on a flat shape. But as influences become stronger in affecting the outcome of a certain test, the shape of the curve becomes less like that of a random test and will take on more of a bell-shaped curve.

The stronger the influence, the stronger the shaping effect on the curve. It is the nature of tests to come out with a disordered, random, or flat-shaped curve. If some values occur much more commonly than others, it is not an accident. The stronger the tendency for obtaining a certain result over others, the stronger the likelihood that there must be a very strong influence. So in that sense, the flatter the curve, the more random its nature, and the less specifically the values of a particular test are being influenced. The more peaked the curve, the more likely it is that there is a very specific reason for the peaking, and the more meaningful the test may be (See above Diagram).

Limitations Of Thyroid Blood Tests As it turns out, there is a very good reason that thyroid hormone blood tests are not always of great predictive value in the resolution of the symptoms of decreased thyroid system function.

It's because thyroid hormones don't have their action in the bloodstream, they have their action at the site of the nuclear membrane receptors of the cells. The thyroid hormones, especially T3, interact with the thyroid hormone receptor much the same way a key interacts with a lock so that it may be opened.

At this time, in spite of our vast technology, there is no way to measure that action. Not for the past forty years, not now, and probably not for another twenty years, can that be measured directly. Historically, doctors have tried to estimate or predict that action based on what floats around in the bloodstream. But common sense tells us that, at best, these blood tests are just an indirect measure of what happens at the cells. And the symptoms of DTSF are caused specifically by low body temperature pattern abnormalities resulting from inadequate thyroid hormone stimulation of the thyroid hormone receptor sites.

So blood tests are very useful in assessing the function of the glands of the thyroid system, however, they are frequently hard to correlate with the onset and resolution of the symptoms of DTSF. The symptoms of DTSF ultimately depend on what happens in the cells of the body, not the bloodstream. Therefore, the thyroid hormone blood tests are useful in assessing the function of the glands of the thyroid system, but cannot and do not directly measure where the "rubber meets the road" in terms of the presence or absence of the symptoms of DTSF.

Most cases of DTSF are caused by Wilson's Temperature Syndrome. Since WTS is an impairment in the peripheral conversion of T4 to T3 (outside the glands of the thyroid system), it is easy to understand why blood tests are not very predictive in directing treatment of the symptoms.

Historically, thyroid blood tests have been used in order to try to estimate what will happen at the active site, but the body temperature can be used to get a better picture of what actually has happened at the active site. Thus, the monitoring of body temperature patterns is a more direct reflection of the adequacy of the thyroid hormone/thyroid hormone receptor interactions of the body.

Since the symptoms are due to abnormal body temperature patterns, it is also easy to understand why body temperature patterns are so useful in the treatment of the symptoms of DTSF. It is the best indicator that we have. So treatment of DTSF that does not take body temperature patterns into consideration, isn't being done correctly. If thyroid hormone/thyroid hormone receptor interactions are ever able to be measured directly, such a measurement will add very little to the predictive value already provided by the body temperature patterns (because the temperature already measures the bottom line: the body temperature!).

These facts have led to a great deal of confusion and frustration. I feel that because the limitations of thyroid blood tests are not always borne in mind, false assumptions are made which is one of the biggest reasons that DTSF is so frequently overlooked.

Do Blood Tests Or Temperature Better Reflect Thyroid Stimulation Of The Cells?
It is well known that thyroid hormone levels and body temperature patterns are related. And, it's known that if thyroid hormone levels in the blood drop to very low levels, then a patient's body temperature can drop well below normal and the patient can even become comatose. It is also well known that patients who have thyroid blood tests that are exceedingly high can often have fevers well over 100 degrees in a condition that is sometimes called "thyroid storm."

When thyroid blood levels go too high, the temperature can go too high, and when thyroid blood levels go too low, the temperature can go too low. In either extreme, severe symptoms can result. So both tests, thyroid blood tests, and temperature tests can both be correlated to conditions and sickness.

Which test, then, is best able to predict when a person is suffering from inadequate thyroid hormone stimulation, or when a person has excessive thyroid hormone stimulation at the site of the thyroid hormone receptors? To help us answer this question, let us consider the shapes of the curves of distribution of values of these tests when they are performed in a large number of people. To do this, let's again remember the principle of entropy, the tendency of all things to go toward disorder. Let us remember, also, that the significance of any test values can be measured, to an extent, by considering how that value compares to what value one would expect in a random situation.

Considering The Thyroid Blood Tests
Thyroid hormones do not grow on trees and they don't exist in nature by accident. That can be demonstrated when one considers that without a thyroid gland there is no thyroid hormone production and, therefore, no thyroid hormone levels would be found in the body. So if the thyroid gland was not present or not functioning, then one would expect to find no hormone. So any thyroid hormone levels detected in the body represent a non-random occurrence.

For our purposes, let us consider four of the more than ten thyroid hormone blood tests available. Generally speaking, ranges of normal contain primarily the central portion of a bell curve (see diagram 4-3). Regardless of how narrow or broad a bell curve, the central portion of the curve contains a constant percentage of the measurements taken.

For our purposes, let us say that percentage is 80%. So that means that the central portion of each bell curve contains 80% of the measured values. In medical tests, normal ranges are often obtained by finding the central portion of the bell curve. The lower end of the central portion is represented by the "lower limit" of normal and the upper end of the central portion is represented by the "upper limit" of normal.

Test Lower Limit Upper Limit T4 4.4 ug/dl 13.9 ug/dl TSH 0.4 uIU/ml 6.0 uIU/ml RT3 100 pcg/ml 500 pcg/ml T3 55 ng/dl 171 ng/dl

Let us now consider the upper and lower limits of normal for four of the thyroid hormone blood tests available (Refer to above table). The first test to be considered is the T4 test. The lower limit of normal equals 4.5, and the upper limit of normal equals 13.0 micrograms per deciliter.

The second test is TSH. Lower and upper limits of normal are 0.4 and 6.0 microinternational units per milliliter respectively.
The third is Reverse T3 (RT3). 100 is the lower limit of normal and 500 picograms per milliliter the upper.
The fourth test is T3, lower limit of normal is 55, upper limit, 171 nanogram per deciliter.

Considering that in the random situation one would expect no thyroid hormone levels to be present, since they are not formed out of the blue by themselves, then these upper and lower limits of normal can be considered to represent a certain number of units above what one would consider random. Referring back to diagram 4-4 of a random curve, a broad curve, and a very peaked curve, you can see that the random curve is flat which causes the two ends of the "central portion of the curve" to be as far as part as possible. In the broader bell-shaped curve, one can see that the upper and lower ends of the central portion of the curve are closer together yet still wide apart. In the extremely peaked bell-shaped curve, the two ends of the central portion of the curve are extremely close together. So, the closer together the ends of the central portion of the curve, the more peaked the curve is. The more peaked the curve, the more dissimilar the curve is to that of a random situation.

Let us now consider, in percentage form, how far apart the ends of the central portion of the curves are for the four thyroid hormone blood tests previously discussed. With T4, the upper limit of normal is 2.9 times higher than the lower limit of normal. For TSH, the upper limit is 15 times higher than the lower limit of normal. For RT3 the upper limit is 5 times higher than the lower limit, and with T3 the upper limit of normal is 3.1 times the lower limit of normal. Therefore, in a T4 test, there is a 190% difference between the upper and lower limit of normal. For TSH there is a 1400% difference. For RT3 there is a 400% difference. And with T3, there is a 210% difference between the upper and lower limits or normal. One can see by these considerations that the TSH curve is much broader than the T4 and T3 curves. Therefore, the TSH curve more closely approaches the shape of a curve of a random situation.

Considering The Body Temperature's Range Of Normal
When one considers that it would be the natural tendency of a body to be the same temperature as its surroundings, then one may consider the number of degrees a body temperature is above room temperature to be the number of units away from what one would consider a random situation. We shall use 75 degrees as room temperature. Fever is considered to be 100 degrees Fahrenheit and we will consider this to be the upper limits of normal. 97.0 degrees is probably lower than the lower end of the central portion of the curve for body temperature, but for our purposes we will consider this to be the lower limit of normal. 100 degrees minus 75 degrees equals 25 degrees, which we will consider the upper limit of normal as compared to the random situation (room temperature). 97.0 degrees minus 75 degrees is 22.0 degrees which we will consider the lower limit of normal above the random situation. 25 degrees is 1.14 times higher than 22.0 degrees and therefore, the upper limit of normal is 14% greater than the lower limit of normal. We can see by comparing this percentage difference to the percentage differences of the thyroid hormone blood tests that the ends of the central portion of the temperature curve are much closer to each other than the ends of the central portion of any of the thyroid test curves. This indicates a much less random situation, therefore, there must be an extremely strong influence involved. This 14% difference between the upper and lower limits of normal is especially interesting when compared to the hundreds and hundreds of percentage points difference in the upper and lower limits of the thyroid blood tests.

Extremely peaked bell curves do not happen by accident and the greater the peaking, the less accidental the situation. Again, they are about as likely as tossing a deck of cards in the air and having them land as a card house. The values of the thyroid hormone blood tests and the body temperature are related to the extent that extremely low blood values can be related to extremely low temperatures and extremely high blood values can be related to extremely high temperatures; and both the thyroid hormones and body temperature are intimately related to the thyroid hormone/thyroid hormone receptor interaction at the nuclear membrane of the cells.

The question remains, which test better reflects the influence and purpose of the all important thyroid hormone/thyroid hormone receptor interaction? Since they are related, it would seem that if it were critical that the body maintain a particular set of values for the thyroid blood tests, then the body temperature patterns would vary widely from person to person to accommodate specific thyroid blood test values. Conversely, if it were critical that the body maintain a particular body temperature level, then it would make sense that the thyroid blood tests values would vary widely to maintain a certain body temperature level. When one considers that the percentage difference between the upper and lower limits of normal for TSH are 1400%, and the percentage difference between the upper and lower limits of normal for the body temperature is 14%, it's easy to see which curve more represents a nonrandom situation and which one fluctuates widely to keep the other at a certain level. It appears that the thyroid hormone blood levels are regulated to fluctuate widely in order to provide for the temperature rather than the other way around. If it is the purpose of the thyroid hormones to fluctuate widely to ensure a certain temperature, then would the thyroid hormone that fluctuates the widest be any more important than the others in accomplishing that purpose?

It is interesting to see that the TSH (thyroid stimulating hormone) test has the widest range of normal of the thyroid blood tests, suggesting that it may be designed, more than any other thyroid system hormone, to ensure a normal body temperature pattern. It is interesting, because TSH is the blood test currently regarded as the most sensitive reflection of thyroid gland function. But if TSH is regulated to fluctuate widely to help ensure a normal temperature pattern, then it is easy to see how the best indicator of the adequacy of the process is the end result, the body temperature, itself.

For example, the study habits of students who are trying to score well on a certain test may vary widely. A more confident student may decide not to study very hard, while one with less background might choose to be more diligent. One could try to measure the adequacy of their preparation for the test by how hard they studied, but a more accurate method would be by their actual scores.

Some people consider body temperature patterns to be a more vague and non-conclusive reflection of thyroid system function, because, "everyone's different, and a lot of people have body temperatures that are lower than the average." This is an unusual argument, considering that just as many people have thyroid blood studies that are lower than the average, and their values vary to a much greater degree than do their body temperature patterns. We must remember that the "ranges of normal" are arbitrarily set in an attempt to make the thyroid tests as useful as possible. Thyroid hormone blood tests are invaluable in helping to evaluate and regulate the thyroid system, especially the portion in which the function of the glands are important. However, the fact that there is only a 14% difference between the upper and lower limits of normal for body temperature readings indicates that the body temperature readings far better reflect the status of the thyroid hormone stimulation of the thyroid hormone receptors.

This leads me to believe that the thyroid hormone/ thyroid hormone receptor interactions are regulated in such a way as to provide such specific and consistent body temperature patterns for an extremely important purpose. And I believe that extremely significant purpose is to help provide the optimal conditions for the enzymatically-catalyzed reactions of the body, thereby affecting virtually every bodily function. Thus, the reason for the maintaining of extremely specific and consistent body temperature patterns is that essentially all the bodily functions depend upon it. Since thyroid blood tests fluctuate widely, it is easy to see why temperatures end up having much greater predictive value, in relation to the symptoms of DTSF, than thyroid hormone blood tests. Just because a test is more expensive or difficult to perform does not necessarily mean it is better or more useful.
 

There's Even A Word For It: Hypochondria
Somewhere along the line, someone noticed that when patients go to the doctor with specific complaints, many times they can be diagnosed easily and treated effectively. On the other hand, when patients go to the doctor with a long list of generalized complaints, it is often more difficult to ascertain the diagnosis and to find a suitable treatment. So it may have been incorrectly concluded that the patients with the more generalized complaints were healthy, having no physical problems, since the level of medical technology available at the time was unable to provide a reasonable explanation for the patients' complaints.

This may be what has led to the sentiment that when patients go to the doctor with a few well-circumscribed complaints they are sane, good people with a medical problem. When patients go to the doctor with a long list of non-specific, generalized complaints, they are more likely to be thought of as fakers, hypochondriacs or a little bit odd. As a matter of fact, I was taught this rule of thumb in medical school. I remember our class being taught that if a patient came in with a hand-written list of complaints, that red flags should go up in our minds as an alert that these patients might have a large hysterical or psychosomatic component to their complaints. The reasoning offered was, that if they had to write the complaints down, then they must not be very significant (if they couldn't remember them without notes), or that they were probably fishing for attention.

I remember having had a hard time understanding that reasoning then, and I continue to struggle with it now. Especially when I consider that it is possible that patients can have a large multitude of complaints, some of which may come and go at different periods of time. It seems understandable to me that under the pressure of being asked point blank by a doctor what he is complaining of, that the patient might have a hard time remembering all the complaints. And it is understandable how patients would want to write their complaints down to ensure that their money is well spent on the time they have with the doctor and so that they do not leave some of their questions unanswered. This circumstance is so pervasive in the medical profession that there is even a word for it: Hypochondriasis. A hypochondriac is a person affected with hypochondriasis. The definition of a hypochondriac out of Dorland's Medical Dictionary is: "A person who has an unhealthy apprehension about one's health, with numerous and varying symptoms that cannot be attributed to organic disease." But just because a person's complaints cannot be attributed to organic disease with available medical technology does not necessarily mean that they are not due to organic disease, nor does that necessarily make the person's apprehension about his health neurotic. And just because a patient has numerous and varying symptoms does not necessarily mean that they are not due to organic disease.

This sentiment has also helped the word, "hypochondriac," to take on a derogatory nature. Patients I know are aware of this sentiment because many times they will comment to me, as they sheepishly rehearse their physical complaints, that they hope that I don't think they are a hypochondriac. It is clear from their comments that they are aware that people who notice and complain of a large number of symptoms are often thought of as complainers with no real problem. In fact, there is nothing unexpected or unusual about a patient having a larger number of generalized complaints when he has a medical problem that is affecting a more fundamental level of the body's organization. Indeed, it would be more surprising if there weren't a large number of related complaints. It's understandable, then, why patients are often reluctant to recount all of their aches, pains, symptoms, and complaints to their physicians. Many times a patient will only volunteer one symptom or maybe two, usually pointing out those that are the most bothersome. It is interesting that if a doctor asks the patient the right questions, he may find that the patient suffers from quite a few more complaints.

What is strange is that since