The thyroid is a small gland in your neck that sets the pace of your body: your energy, weight, heart rate and temperature. Thyroid problems are common in India, and women are several times more likely to have one than men.
What the tests measure
- TSH (thyroid stimulating hormone) is made by the brain to tell the thyroid how hard to work. It is usually the first and most useful test.
- T4 and T3 are the hormones the thyroid itself makes. A thyroid profile measures them with TSH, to show how the gland is responding.
What the results usually mean
- High TSH with low T4 usually means an underactive thyroid (hypothyroidism): tiredness, weight gain, feeling cold, dry skin, constipation, heavy periods.
- Low TSH with high T4 or T3 usually means an overactive thyroid (hyperthyroidism): weight loss, a racing heart, feeling hot, anxiety, tremor.
- A slightly high TSH with normal T4 is common. Your doctor may simply repeat the test after a few weeks.
Most labs place a normal adult TSH roughly between 0.4 and 4.5. Read your result against the range printed on your report, as it differs between labs, and is different again in pregnancy.
Preparing for the test
- No fasting is needed for thyroid tests on their own.
- If you take a thyroid tablet, ask your doctor whether to take it before or after the sample is drawn on test days.
- Tell your doctor if you take biotin, often found in hair, skin and nail supplements. It can affect the result, and you may be asked to stop it for a couple of days before the test.
- For follow-up tests, try to give the sample at about the same time of day each time.
Who should get tested
Anyone with the symptoms above, women planning a pregnancy or in early pregnancy, people with a family history of thyroid disease, and anyone already on thyroid treatment, whose dose is checked with regular TSH tests.
