Underactive thyroid (hypothyroidism)Causes

An underactive thyroid (hypothyroidism) is when your thyroid gland does not produce enough of the hormone thyroxine (also called T4).


An underactive thyroid is where your thyroid gland (a small gland in your neck) does not produce enough hormones.


An underactive thyroid is treated with medicine that raises the level of thyroid hormone in your body.


Symptoms of an underactive thyroid include feeling tired all the time, gaining weight and being sensitive to cold.

Page last reviewed: 27/04/2018
Next review due: 27/04/2021