Malfunctioning thyroid symptoms are remarkably common, however, many patients that report these symptoms are told by their primary care doctors that their symptoms are “normal.” A typical test performed by a primary care physician to determine the cause of damaged thyroid glands is really nothing but an assumption about what a person’s hormone levels are downstream. The test, or lab, that informs this prognosis is called a TSH (Thyroid Stimulating Hormone). TSH stimulates the thyroid gland to produce T4. T4 then feeds back to the pituitary gland dictating how much TSH is produced. It is a feedback loop and though the assumptions are simple there are a few outstanding issues including:
3 Things You Need To Know About Subclinical Hypothyroidism
– T4 is inactive in the body. It needs to be converted to T3 to have an effect. Many people lack conversion factors and are not actually converting to any active hormones. Every cell in your body has a receptor for T3 (active thyroid hormone). This is why the symptoms of low thyroid function can be so varied. You may have plenty of T4 and a normal TSH, but if you aren’t converting to T3 then you still have all the thyroid symptoms.
– A major site of this conversion is in the liver. In the state of today’s society, most people have problems with liver congestion. This equates to decreased thyroid conversion and decreased thyroid function even though your TSH is “normal.”
– Most importantly, the feedback loop from T4 to TSH is inhibited by cortisol, a stress hormone. So if you are under stress, the feedback loop determining your level of TSH is broken, rendering the value of TSH useless in detecting low thyroid hormone.