HealthWise KnowledgeBase
Thyroid-Stimulating Hormone (TSH)
Results
A thyroid-stimulating Reference hormone Opens New Window (TSH) blood test is used to check for Reference thyroid gland Opens New Window problems.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Results are usually available in 2 to 3 days.
| Adults: |
0.4–4.2 microunits per milliliter (mcU/mL) or 0.4–4.2 Reference milliunits per liter (mU/L) Opens New Window |
|---|---|
| Children: |
0.7–6.4 mcU/mL or 0.7–6.4 mU/L |
| Newborns ( 1-4 days): |
1–39 mcU/mL or 1–39 mU/L |
High values
High TSH levels may be caused by:
- An underactive thyroid (Reference hypothyroidism Opens New Window). Reference Hashimoto's thyroiditis Opens New Window is the most common cause of primary hypothyroidism.
- A pituitary gland tumor that is making too much TSH. This is uncommon.
- Not taking enough thyroid hormone medicine for treatment of an underactive thyroid gland.
Low values
Low TSH levels may be caused by:
- An overactive thyroid gland (Reference hyperthyroidism Opens New Window). Causes of hyperthyroidism include Reference Graves' disease Opens New Window, a type of Reference goiter Opens New Window (toxic multinodular goiter), or a noncancerous (benign) tumor called a toxic nodule.
- Damage to the pituitary gland that prevents it from making TSH (a condition called secondary hypothyroidism).
- Taking too much thyroid medicine for treatment of an underactive thyroid gland.
- Pregnancy during the first Reference trimester Opens New Window.
| By: | Reference Healthwise Staff | Last Revised: Reference April 5, 2012 |
| Medical Review: | Reference E. Gregory Thompson, MD - Internal Medicine
Reference Matthew I. Kim, MD - Endocrinology |
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This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Reference Terms of Use. Reference How this information was developed to help you make better health decisions.
