Common questions
How do you test for a thyroid problem?
A TSH (thyroid-stimulating hormone) blood test is the first-line screen. A high TSH usually points to an underactive thyroid and a low TSH to an overactive one; clinicians may add free T4, free T3, or thyroid antibody tests to find the cause.
Can menopause be mistaken for a thyroid problem?
Yes. Fatigue, weight changes, mood shifts, poor sleep, and palpitations occur in both perimenopause and thyroid disease, which is exactly why a TSH blood test is useful — it can tell them apart.
What does a normal TSH with clear symptoms mean?
Usually that the symptoms have another cause — most often iron deficiency, sleep apnea, depression or perimenopause itself, all of which mimic hypothyroidism closely. It can occasionally mean a pituitary problem, where TSH is unreliable, but that is rare and comes with other signs.
Can supplements interfere with a thyroid test?
Biotin does, and badly. High-dose biotin, found in most hair, skin and nail supplements, distorts the laboratory method used for many thyroid tests and can produce results that look like Graves' disease in someone with a normal thyroid. Stop it for at least two days before testing.
Why is levothyroxine timing so strict?
Because absorption is easily blocked. Calcium, iron, magnesium and antacids bind it in the gut, coffee reduces absorption by up to 30%, and soy and high-fibre meals interfere. Take it on an empty water-only stomach and leave four hours before calcium or iron — most reports of levothyroxine not working are absorption, not dose.