Скачать или смотреть Clinical Approach To Subclinical Hyperthyroidism

Subclinical hyperthyroidism is a condition in which you have low levels of thyroid stimulating hormone (TSH) but normal levels of T3 and T4.

T4 (thyroxine) is a major hormone secreted by your thyroid gland. T3 (triiodothyronine) is a modified version of T4. The amount of T4 produced by your thyroid gland is controlled by the levels of TSH production by your pituitary gland and vice versa.

Therefore, if your pituitary gland sees very little T4, it will produce more TSH to tell your thyroid gland to produce more T4. Once the amount of T4 reaches appropriate levels, your pituitary gland recognizes that and stops producing TSH.

In people with subclinical hyperthyroidism, the thyroid produces normal levels of T4 and T3. Yet, they have lower-than-normal TSH levels. This imbalance of hormones leads to the condition.

The prevalence of subclinical hyperthyroidism in the general population is estimated to range from 0.6 to 16 percent.