The thyroid is a small gland in the neck that controls how your body uses energy. When it makes too little or too much hormone, it can affect weight, mood, energy, periods and heart rate. Thyroid problems are common in India, especially among women.

The tests in a thyroid profile

• TSH (Thyroid Stimulating Hormone): the most sensitive screening test. A high TSH usually points to an underactive thyroid (hypothyroidism); a low TSH to an overactive one (hyperthyroidism).
• T3 and T4: the hormones the thyroid itself produces. Free T3 and Free T4 measure the active, unbound portion.
• Anti-TPO antibodies: help identify autoimmune thyroid disease such as Hashimoto’s thyroiditis.

Symptoms worth testing for

• Tiredness, weight gain, feeling cold, dry skin or hair fall
• Weight loss, palpitations, anxiety or excessive sweating
• Irregular periods or difficulty conceiving
• A swelling in the front of the neck

Reference ranges vary between laboratories and change during pregnancy, so your result should always be read by your doctor alongside your symptoms. No fasting is required for a thyroid test, though morning samples are preferred if you take thyroid medicine.