THYROID DEFICIENCY: SOURCES OF NEGLECT AND CONFUSION

It's impossible to overemphasize the importance of the thyroid, a small, butterfly-shaped gland located in the neck and weighing less than an ounce. It is the thyroid which controls metabolism—the process by which food is transformed into energy and many vital chemical changes take place. Minute thyroid secretions, something less than a spoonful a year, are responsible for much of the body's heat production. They help maintain the circulatory system and blood volume. They are necessary for muscle health. They heighten sensitivity of nerves. Every organ, every tissue, every cell is affected by the hormone secretions of the gland.

That severe hypothyroidism can have devastating effects has long been appreciated. A cretin child, born with a grossly defective thyroid gland, will remain a dwarf and become an idiot unless given thyroid to make up for the gland's total or near-total failure to produce secretions.

A severely hypothyroid adult, whose gland produces grossly inadequate amounts of secretions, may have a "moon-shaped" face, coarse features, thick nostrils and lips, slow and thick speech, and suffer from weakness and listlessness to the point of apathy.

Fortunately, extreme hypothyroidism is rare. But mild or moderate hypothyroidism is far from rare. And the results of it can be confusing. There are none of the classic gross changes in physical features that occur with the extreme form. Instead, there can be varied symptoms that may seem, on the surface, far removed from the thyroid.

One of the most common symptoms is fatigue. It can vary from relatively mild to severe. It may come on so slowly that a victim, feeling no sudden, precipitous decline in energy level, may come to accept fatigability as—for him—a virtually normal state.

In one case, low thyroid function may give rise to fatigue alone; in another, fatigue may be present but of lesser importance compared with, say, recurrent severe headaches. In other cases, there may be other symptoms, sometimes a whole complex of symptoms. Repeated infections, skin problems, menstrual disturbances of many kinds, memory disturbances, concentration difficulties, depression, paranoid symptoms—these are just a few of many possible manifestations.

Unless it is recognized that low thyroid function can have many effects which may vary considerably from one victim to another, the possibility that this is where the trouble may lie may never even be considered. In my experience, many patients with problems labeled "psychosomatic"—and many who have been classified as being hypochondriacs—are victims of unrecognized hypothyroidism.

Failing Tests

One source of confusion has been the failure of standard thyroid function tests to detect hypothyroidism reliably. The basal metabolism test, for example, one of the very first to be used, checks thyroid function by measuring oxygen consumed when the body is at rest —doing nothing but sustaining itself. When hypothyroidism is pronounced, the test may pick it up but otherwise may not. There are, as we shall see, good reasons why it is—virtually has to be—often inaccurate.

Other tests, such as protein-bound iodine and radioactive iodine uptake, may also not always be dependable, although for a long time they were considered reliable. In fact, The Medical Letter, an independent medical-evaluation bulletin for physicians, recently has warned that many commonly used drugs—and even shampoo and skin antiseptic compounds—can upset test results.

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