what does an underactive thyroid cause
Underactive thyroid (hypothyroidism) Underactive thyroid (hypothyroidism) The thyroid gland in the neck is important for regulating the body's metabolism. With an underactive thyroid, also called hypothyroidism, the thyroid gland does not make enough of the thyroid hormone called thyroxine. This can make someone feel tired, gain weight, feel depressed, feel more sensitive to the cold, have dry skin and hair or experience muscle aches.