Low TSH level in the blood

If you need to know which are the TSH reference ranges or you require more information about the role of TSH in the blood, you can visit normal TSH level in the blood

A TSH (thyroid-stimulating hormone) level in the blood lower than normal range may be a sign of primary hyperthyroidism, a disorder where when the thyroid gland produces too much of the thyroid hormone. For that reason, thyroid hormones T3 (triiodothyronine) and T4 (thyroxine) will be higher than normal.

However, there is a rare situation where the TSH values are low due to a failure of the pituitary gland. In this case, T3 and T4 values will be also lower than normal and it is related to a disorder called secondary hypothyroidism.

TSH (thyroid-stimulating hormone) is also called thyrotropin or thyrotropic hormone.

In the International System of Units (SI), TSH in the blood is measured in mU/L. The numeric values in this case are the same in µUI/ml or in mU/L.

The following diseases can explain a TSH level in the blood lower than normal:

If the TSH level in the blood is low, the following tips can help you:

• Reduce your iodine intake if it is excessive.
• Talk to your doctor about the possible interference of the drugs that you are taking.
• If your doctor considers it appropriate he will prescribe you antithyroid drugs such as propylthiouracil or thiamazole to reduce T3 and T4 hormones and that way the TSH will increase.

The following values are considered to be above the normal range:

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.