TSH (Thyroid-stimulating hormone) Test Test
A TSH test measures the level of thyroid-stimulating hormone in your blood. It helps find out if your thyroid gland is working properly and can show if you have too much or too little thyroid hormone.
What this test measures
TSH stands for thyroid stimulating hormone. A TSH test is a blood test that measures this hormone. TSH is made by the pituitary gland and tells your thyroid how much thyroid hormone to make.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
If your TSH level is too high, it may mean your thyroid is not making enough thyroid hormone (hypothyroidism). Your pituitary gland makes more TSH to try to stimulate your thyroid.
Lower-than-normal results
If your TSH level is too low, it may mean your thyroid is making too much thyroid hormone (hyperthyroidism). Your pituitary gland makes little or no TSH.
Frequently asked questions
What is TSH?
TSH stands for thyroid stimulating hormone. It is made by the pituitary gland and tells your thyroid how much thyroid hormone to make.
Why do I need a TSH test?
A TSH test is used to find out how well your thyroid is working. It can tell if you have hyperthyroidism (too much thyroid hormone) or hypothyroidism (too little thyroid hormone).
What does a high TSH level mean?
A high TSH level may mean your thyroid is not making enough thyroid hormone (hypothyroidism). Your pituitary gland makes more TSH to try to stimulate your thyroid.
What does a low TSH level mean?
A low TSH level may mean your thyroid is making too much thyroid hormone (hyperthyroidism). Your pituitary gland makes little or no TSH.
Can a TSH test show the cause of a thyroid problem?
No, a TSH test cannot show what is causing a thyroid problem. Your provider may order other thyroid tests like T4, T3, or thyroid antibodies tests to find the cause.
Related lab tests
Sources
- MedlinePlus: TSH (Thyroid-stimulating hormone) Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.