TSH Test

Know More About This Test

TSH (Thyroid Stimulating Hormone) is a hormone produced by the pituitary gland that regulates thyroid hormone production (T3 and T4). It maintains body metabolism, energy, and temperature. Even small changes in TSH can cause major symptoms. It is considered the most sensitive thyroid screening test.

Why Is This Test Recommended?

TSH testing is recommended for suspected hypothyroidism or hyperthyroidism, unexplained weight gain or weight loss, and menstrual irregularities or infertility. It helps investigate fatigue, depression, or anxiety and is used for monitoring thyroid medication response. Normal range is approximately 0.4–4.5 µIU/mL. High TSH indicates underactive thyroid, low TSH indicates overactive thyroid. Subclinical thyroid disease can be detected early, and values vary with age and pregnancy.

What Do the Results Indicate?

Abnormal values need correlation with T3 and T4 levels for complete diagnosis. Repeat testing confirms the diagnosis. Results guide medication dosage adjustment, with lifelong monitoring required in many cases. Pregnancy requires tighter control of thyroid function.

How Is the Test Performed and Prepared For?

A blood sample is drawn from a vein. No fasting is required. The test is best done in the morning for consistency. Inform your doctor about thyroid medicines as they may affect results. It is a safe and quick procedure.

Frequently Asked Questions (FAQs)

Is TSH enough to diagnose thyroid disease?

Often yes; TSH is the most sensitive initial screening test for thyroid function.

Can stress affect TSH?

Mildly; severe stress may cause minor fluctuations but usually doesn't significantly alter diagnosis.

How often should it be tested?

As advised; depends on whether you're on treatment, newly diagnosed, or being screened.

Does fasting change result?

No; fasting does not affect TSH levels significantly.

Is TSH affected by pregnancy?

Yes; pregnancy alters TSH reference ranges, requiring adjusted interpretation and monitoring.