Thyroid test (TSH): who needs one?
A thyroid test is not a routine screening for adults without symptoms: the USPSTF found the evidence insufficient to recommend for or against it. Doctors still test when there are symptoms, risk factors or a known thyroid condition. The bodies differ a little, and your doctor decides. (USPSTF, 2015) (MedlinePlus, 2024)
What each body says
| Body | Position |
|---|---|
| USPSTF (2015, still final) | Nonpregnant adults without symptoms: evidence insufficient (I statement); a May 2024 literature scan found no new evidence to support an update (USPSTF, 2015) |
| American Thyroid Association and American Association of Clinical Endocrinologists | As summarized by the USPSTF: consider screening for an underactive thyroid in people older than 60; actively look for it in people at increased risk and in women planning pregnancy; no screening of everyone (USPSTF, 2015) |
When doctors test anyway
- Symptoms of too much or too little thyroid hormone. (MedlinePlus, 2024)
- Taking thyroid hormone medicine, or after thyroid removal or treatment for an overactive thyroid: regular TSH tests check the dose and levels. (MedlinePlus, 2024)
- Higher risk of an underactive thyroid: being a woman, being older than 60, a past thyroid problem, surgery or radioactive iodine, radiation to the neck or chest, a family history of thyroid disease, pregnancy in the past 6 months, Turner syndrome, or conditions such as celiac disease, type 1 or type 2 diabetes, rheumatoid arthritis, lupus, Sjögren's syndrome or pernicious anemia. (NIDDK)
- An overactive thyroid is also more common in women, people older than 60 and people with a family history of thyroid disease. (NIDDK)
What TSH results mean, in plain words
TSH is a hormone from the pituitary gland that tells the thyroid how much hormone to make. A high TSH most often means an underactive thyroid (hypothyroidism). A low TSH usually means an overactive thyroid (hyperthyroidism). If TSH is not normal, you will need at least one other test, such as T4, T3 or thyroid antibodies, to find the cause. (NIDDK) (MedlinePlus, 2024)
TSH can be off when the thyroid is healthy: some serious illnesses lower it for a short time, it may be higher in people over 80, and pregnancy affects it. (MedlinePlus, 2024) Your doctor reads your result with your symptoms and history. More on patterns, ranges and repeat tests: thyroid test results.
Questions people ask
Should I get my thyroid checked every year?
Not as a routine screening if you have no symptoms. The USPSTF found the evidence insufficient to recommend for or against screening nonpregnant adults without symptoms (I statement, 2015), and a 2024 literature scan found no new evidence to update it. Your doctor may still test for a reason. (USPSTF, 2015)
Do other groups recommend thyroid screening?
As the USPSTF summarizes them, the American Thyroid Association and the American Association of Clinical Endocrinologists recommend considering screening for an underactive thyroid in people older than 60, and looking actively in people at increased risk and in women planning pregnancy, but not screening everyone. (USPSTF, 2015)
What does a high or low TSH mean?
A high TSH most often means an underactive thyroid (hypothyroidism); a low TSH usually means an overactive thyroid (hyperthyroidism). If the result is not normal, you will need at least one other test to find the cause. Your doctor reads the result. (NIDDK) (MedlinePlus, 2024)
Can TSH be off when the thyroid is healthy?
Yes. Some serious illnesses can lower TSH for a short time, TSH may be higher in people over 80 without thyroid problems, and pregnancy affects TSH. (MedlinePlus, 2024)