(Help My Chronic Condition and Pain website)
Have you been told your two main thyroid blood markers (TSH and T4) are normal, yet you suffer with a laundry list of thyroid symptoms? This scenario is extremely common. It makes you wonder if you truly have a thyroid problem.
How is it possible to have thyroid problems with normal labs?
Let me explain.
There are two main forms of thyroid hormone. Thyroxine, commonly called T4, and triiodothyroxine, commonly called T3. T4 is the inactive form of thyroid hormone, meaning it does not have the ability to bind to cells and create a metabolic response. T3 is the active form of thyroid hormone, responsible for binding to cells and creating metabolic responses.
Your thyroid gland predominantly produces inactive T4. This means that we must convert T4 to T3, which is known as thyroid conversion, in order to have normal thyroid responses. This conversion takes place primarily in the liver and gut mucosa.
So what does this have to do with thyroid symptoms and normal looking labs?
The negative feedback loop between the thyroid and the pituitary gland is with TSH and inactive T4. When T4 levels drop, then TSH elevates to tell the thyroid to produce more hormone. If T4 is elevated, then TSH is suppressed. It also works vice-versa.
So if T4 and TSH look normal on the lab panels, the true problem may never be investigated and the person may go on suffering indefinitely.
When there is underconversion of T4 to T3, we can’t have normal thyroid responses. T4 does us no good if we can’t convert it to an active form. This thyroid underconversion issue is one of the many reasons why patients with hypothyroid symptoms go undiagnosed and mismanaged.
So What Causes Thyroid Underconversion?
Certain inflammatory cytokines involved in the stress response have been shown to down-regulate the enzyme responsible for peripheral conversion of T4 to T3, i.e. when we are stressed, our body’s inflammatory response can lead to underconversion. Fixing this problem requires lab testing to determine the source of the inflammation. It is necessary to also test the hypothalamus-pituitary-adrenal-axis.
By using natural interventions to normalize the faulty physiology, we normalize the T4 to T3 conversion. This is one situation where thyroid hormone replacement would not work because ninety five percent of the time synthetic T4 is administered. Most of the time hypothyroid patients with deficient T3 have trouble converting T4 to T3, so they need specialized help and in some cases a prescription from their medical doctor for synthetic T3 (e.g. Cytomel) as well.
Another source of thyroid peripheral underconversion is increased gastrointestinal lipopolysaccharides (LPS), an endotoxin produced from bacterial overgrowth. The primary cause of this is intestinal dysbiosis, or a shift in the good versus bad bacteria in your gastrointestinal system. Another common reason for increased lipopolysaccharides is Leaky Gut Syndrome (LGS). An important research study shows that LPS is related to major depression, which is frequently seen in patients who have unresolved hypothyroidism. The LGS problem is fixed by doing advanced gastrointestinal lab panels and normalizing the findings, with natural interventions.
I see people everyday who have histories that scream of a thyroid problem, yet they continue to suffer because no one ever looked at the whole picture. T3 levels are rarely ever used in thyroid screening panels, so the T4 to T3 underconversion pattern is rarely found. When it is found, proper testing to determine the source of the underconversion is not investigated. It’s a big problem since this is such a common pattern of thyroid dysfunction.
All the best – Dr. Johnson – Digging Deeper To Find Solutions