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.
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 some improvement of their symptoms of thyroid hormone supplementation with 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.