The most common cause of Grave’s disease is hyperthyroidism. It is an autoimmune disorder, an attack on the thyroid gland by a person’s own immune system.
Graves' disease is an autoimmune disease. It most commonly affects the thyroid, frequently causing it to enlarge to twice its size or more (goitre), become overactive, with related hyperthyroid symptoms such as increased heartbeat, muscle weakness, disturbed sleep, and irritability. It can also affect the eyes, causing bulging eyes (proptosis). It affects other systems of the body, including the skin, heart, circulation and nervous system.
It affects up to 2% of the female population, sometimes appears after childbirth, and has a female:male incidence of 5:1 to 10:1. It has a strong hereditary component; when one identical twin has Graves' disease, the other twin will have it 25% of the time. Smoking and exposure to second-hand smoke is associated with the eye manifestations but not the thyroid manifestations.
Diagnosis is usually made on the basis of symptoms, although thyroid hormone tests may be useful, particularly to monitor treatment.