Thyroid Stimulating Hormone (TSH)
TSH testing will measure the amount of thyroid stimulating hormone produced by the pituitary gland as an indicator of thyroid activity. TSH is part of the body’s feedback system to maintain stable amounts of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The way that Medicare is currently set up means that often if TSH is within the laboratory range no further testing will be covered by, and must be done as an out of pocket expense.
TSH is extremely fragile, hard to balance, and fluctuates each hour. Each laboratory sets their own range, so there is no international government standard and this is why different labs will have different ranges. TSH levels were also set using the “healthy” population to determine them. The question is, what is a healthy population?