If you’re experiencing symptoms of thyroid disorder, you’ll be advised to take a thyroid stimulating hormone (TSH) test. The TSH is the most sensitive marker of peripheral tissue levels of thyroid. Most endocrinologists and physicians assume a normal TSH level means your thyroid is functioning properly. But, normal T3 and T4 levels in your test results do not always mean you have a healthy thyroid.
What Does A Thyroid Stimulating Hormone Test Do
1. Pituitary T3 Levels
Your emotional, mental, and physical state greatly affect the outcome of your TSH results. The TSH is a marker of pituitary levels of T3 and not of T3 levels in other parts of the body like the thyroid. A lot of factors such as physiological stress, depression, diabetes, aging, obesity, and numerous other conditions increase pituitary T3 levels because of diminished cellular and tissue T3 levels. Under these conditions, the TSH test is not a reliable indicator that a person has a normal thyroid. You can have normal pituitary T3 levels, but low T3 levels everywhere else in the body.
2. Free T4 Markers
A TSH test will measure the levels of T4 in the body as an indicator of your thyroid’s condition. TSH, and consequently, T4 levels can be decreased by factors like physiological and emotional stress and illness. But, there are conditions that can reduce tissue levels of T3 to produce free T4, making the TSH test unreliable in determining your thyroid condition using free T4 markers.
3. Reduced Bioactivity of TSH
— endocrinologist (@endo_icq) June 1, 2017
Many individuals will secrete a less bioactive TSH so for the same TSH level, a large percentage of individuals will have reduced stimulation of thyroid activity. Reduced bioactivity of TSH is not detected by current TSH assays used in clinical practice.
4. No Correlation with Tissue Effects
A study shows that a TSH test shows no correlation with tissue effect of thyroid hormones. The study aimed to assess the level of hypothyroidism and peripheral thyroid action on 332 female patients. It was only when they did clinical scores on ankle reflex times the results showed correlation with tissue thyroid effects.
5. Combined with Other Tests
A combination of testing for serums levels of TSH, free T3, free T4, reverse T3, and anti-TPO antibodies should be done in order to have a more accurate clinical analysis of your overall thyroid health. If you want to make sure your results are accurate, you can also add a combination of clinical assessment and measurement of reflex speed and basal metabolic rate. After your initial TSH test results, your doctor will also recommend additional testing for T3, T4, free T3, free T4, and anti-TPO antibodies to accurately finalize your diagnosis.
Watch this video from Wellness Punks to find out more details about the nature of a TSH test!
The actual relationship between the physiology of hypothalamic-pituitary-thyroid axis and tissue regulation of hormones shows that the accuracy of TSH is unreliable in certain conditions. Relying on a simple TSH test for a complete diagnosis of your thyroid’s condition, and choosing to withhold treatment due to positive results, will result in the continuation of your symptoms. For a more accurate diagnosis of your thyroid health, combine your TSH test with other clinical tests.
Have you had a TSH test in the past? Share your experience with us in the comments below!