Men: 0.4 - 4 µUI/ml
Women: 0.4 - 4 µUI/ml
Children from 11 to 18 years old: < 4.3 µUI/ml
Children from 6 to 10 years old: < 4.8 µUI/ml
Children from 1 to 5 years old: < 6 µUI/ml
Newborns: < 15 µUI/ml
In the International System of Units (SI), TSH in the blood is measured in mU/L. The numeric values are the same in µUI/ml or in mU/L.
Each laboratory must establish its own normal ranges for the total TSH (thyroid-stimulating hormone) in the blood. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels, according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.
Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.
There are some circumstances that may alter the normal ranges:
TSH (thyroid-stimulating hormone), also called thyrotropin, is produced by the pituitary gland. TSH plays an important role in the regulation of thyroid hormones. If the level of thyroid hormones (T3 and T4) drops too low, the pituitary gland produces TSH to stimulate the thyroid gland to produce more hormones.
It works along with Thyrotropin-releasing hormone (TRH). The hypothalamus releases thyrotropin-releasing hormone (TRH), which stimulates the pituitary gland to release thyroid-stimulating hormone (TSH).
Thyroid hormones T3 (triiodothyronine) and T4 (thyroxine) plays an important role in the body because they have influence on metabolism, growth, development, heart rate, body temperature or blood pressure.
TSH (thyroid-stimulating hormone) blood test is used to detect thyroid disorders. This test is usually done along with T3 (triiodothyronine) and T4 (thyroxine) hormones. TSH is the test that gives more information about thyroid disorders because a value out of the normal range is usually a sign of a malfunction of the thyroid gland.
The TSH blood level is usually tested in a routine blood test.
High values of TSH in the blood may be a sign of primary hypothyroidism (T3 and T4 are below the normal range). Low values of TSH may be a sign of primary hyperthyroidism (T3 and T4 are above the normal range). Primary hypothyroidism or hyperthyroidism refers to a problem with the thyroid gland.
If the pituitary gland fails, TSH may be lower than normal. This situation is related to secondary hypothyroidism where T3 and T4 hormones will be also lower than normal. Secondary hypothyroidism is not a common disorder.
TSH values are also useful to control people taking thyroid medication. It is an optimal way to know if the dose of the given drugs are adequate for the treatment.
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The following values are considered to be normal values:
IMPORTANT: These levels are expressed in µUI/ml. They are an example of a healthy man of about 45 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.
|0.4 µUI/ml||0.5 µUI/ml||0.6 µUI/ml||0.7 µUI/ml||0.8 µUI/ml||0.9 µUI/ml||1 µUI/ml||1.1 µUI/ml|
|1.2 µUI/ml||1.3 µUI/ml||1.4 µUI/ml||1.5 µUI/ml||1.6 µUI/ml||1.7 µUI/ml||1.8 µUI/ml||1.9 µUI/ml|
|2 µUI/ml||2.1 µUI/ml||2.2 µUI/ml||2.3 µUI/ml||2.4 µUI/ml||2.5 µUI/ml||2.6 µUI/ml||2.7 µUI/ml|
|2.8 µUI/ml||2.9 µUI/ml||3 µUI/ml||3.1 µUI/ml||3.2 µUI/ml||3.3 µUI/ml||3.4 µUI/ml||3.5 µUI/ml|
|3.6 µUI/ml||3.7 µUI/ml||3.8 µUI/ml||3.9 µUI/ml||4 µUI/ml|