I recommend the following panel of laboratory tests if you want to get the best picture of what your thyroid is doing:
TSH -- the high-sensitivity version. This is the BEST test. But beware most all of the “normal” ranges are simply dead wrong. The ideal level for TSH is between 1 and 1.5 mIU/L (milli-international units per liter)
Free T4 and Free T3. The normal level of free T4 is between 0.9 and 1.8 ng/dl (nanograms per deciliter). T3 should be between 240 and 450 pg/dl (picograms per deciliter).
Thyroid antibodies, including thyroid peroxidase antibodies and anti-thyroglobulin antibodies. This measure helps determine if your body is attacking your thyroid, overreacting to its own tissues (ie, autoimmune reactions). Physicians nearly always leave this test out.
For more difficult casesTRH can be measured (thyroid releasing hormone) using the TRH stimulation test. TRH helps identify hypothyroidism that’s caused by inadequacy of the pituitary gland.
Other tests that might be indicated for more complex cases are a thyroid scan, fine-needle aspiration, and thyroid ultrasound. But these are specialized tests that your physician will use only in a small number of cases, in special situations.
Even if all your lab tests are “normal,” if you have multiple thyroid symptoms, you still could have subclinical hypothyroidis
