Osmosis video - Hypothyroidism

Hypothyroidism refers to a condition where there's a lack of thyroid hormones (triiodothyronine (T3) and thyroxine (T4)), which normally help control the body's metabolism.

Hypothyroidism can be primary or secondary. In primary hypothyroidism, the thyroid gland isn't working properly, because of an autoimmune disease like Hashimoto's thyroiditis, hyperthyroidism treatment, or a congenital defect. In secondary hypothyroidism, either the anterior pituitary gland or the hypothalamus is the problem, usually because of a tumor or damage from surgery.

Symptoms of Hypothyroidism include weight gain, mental slowness, swelling in the skin and soft tissues, and a slower heart rate.