TSH Test

This test is used to measure the levels of thyroid stimulating hormone (TSH) in the blood. The thyroid stimulating hormone is a pituitary hormone that stimulates the thyroid gland to produce triiodothyronine (T3) and thyroxine (T4) hormones. These hormones help to control the rate at which energy is used in almost every tissue in the body.

Why this test is performed?

This test is one amongst many tests that may be helpful to determine if the thyroid gland is functioning normally. The thyroid gland is a part of the endocrine system. It produces and releases the thyroid hormones into the bloodstream. The hormones produced by the thyroid gland regulate various functions in the body including heart function, digestive function, bone maintenance, brain development, muscle control, metabolism (the rate at which the body uses energy), etc.

This test is used to identify if the thyroid gland is hyperactive (hyperthyroidism) or underactive (hypothyroidism). Hyperthyroidism is a condition where the thyroid gland produces too many hormones. This condition may cause signs and symptoms such as a sudden weight loss, irritability, sweating, irregular heartbeats, etc. Hypothyroidism is a condition where the thyroid gland does not produce enough amount of hormones. This condition may cause signs and symptoms such as a sudden weight gain, dry skin, constipation, feeling cold, slow heart rate, etc. Your doctor may ask you to undergo this test if you are suffering from any such symptoms.

If you are suffering from a thyroid disorder and receiving treatment for the same, your doctor may advise you to undergo this test as part of routine monitoring as well as to determine the effectiveness of the treatment.

Frequency of testing:

If you are a healthy individual above the age of 35, your doctor may advise you to undergo this test either on a yearly basis or every other year. If you have been diagnosed with a thyroid disorder, your doctor may advise you to undergo this test once every 3 months to once a year based on your clinical condition.

Precautions:

Drugs such as carbimazole, methimazole, etc. may affect the results of this test. Hence, all medications should be reported to the doctor before undergoing this test.

If you are a healthy individual and the test results are in normal range, then the thyroid gland is functioning normally and there is no need for medical intervention.

If you have been diagnosed with a thyroid disorder and the test results are in the normal range, then the treatment you are receiving is working effectively.

If the thyroid stimulating hormone levels are above the normal range, it may be indicative of hypothyroidism, insufficient thyroid hormone replacement therapy, Hashimoto's thyroiditis (an auto-immune disorder, where the immune system of the body attacks the thyroid gland), etc. Other factors such as lithium treatment, external neck irradiation, neonatal period, period post subtotal thyroidectomy (surgical removal of all or a part of the thyroid gland) may also be responsible for the increased levels of the thyroid stimulating hormone in the blood.

If the level of the thyroid stimulating hormone is below the normal range, then it may be indicative of hyperthyroidism, Grave’s disease (an immune system disorder which results in the overproduction of thyroid hormones), thyroiditis (inflammation of the thyroid gland), toxic multinodular goiter, thyroid adenoma (benign tumor of the thyroid gland), etc.