Graves’ disease is the most common cause of overactive thyroid. It can run in families and can occur at any age, although it is most common in women aged 20-40 years old. You are more likely to develop Graves’ disease if you smoke.
Graves’ disease is an autoimmune condition. This means the immune system mistakes something in the body for a toxic substance and attacks it.
In Graves’ disease, it attacks the thyroid gland, which leads to an overproduction of the thyroid hormones.
It is not known what triggers the immune system to do this. Like many autoimmune conditions, it is thought that a combination of both genetic and environmental factors could be involved.
If you have Graves’ disease, your eyes may also be affected, causing discomfort and double vision. This is known as Graves’ ophthalmopathy. You may find your eyes bulge out or appear more prominent.
For more information on Graves’ ophthalmopathy, read our page on complications of an overactive thyroid gland.