The thyroid gland is a part of the body’s endocrine (hormone) system – which is made up of the glands that help regulate many of the body’s different functions. If the thyroid gland is overactive, it produces too much of the thyroid hormone thyroxine. An overactive thyroid (medical term: hyperthyroidism) can be caused by various things. The most common cause is a condition known as Graves’ disease.
The higher levels of thyroid unnecessarily speed up a lot of functions in the body. This can lead to noticeable symptoms such as weight loss, sweating, nervousness or a rapid heartbeat. An overactive thyroid increases the risk of cardiovascular disease (problems affecting the heart and/or blood vessels).
If the thyroid gland doesn’t produce enough , the body’s functions slow down. This problem is known as an underactive thyroid or hypothyroidism.