Autoimmune Thyroiditis is the most common cause of Hypothyroidism in Ireland.
This occurs when your body produces antibodies to the thyroid gland which ‘attack’ it, preventing it from functioning properly.
In some patients, this will cause the thyroid gland to enlarge. This is known as a Goitre. If this occurs when you have Autoimmune Thyroiditis, it is called Hashimoto's Disease.
Other less common causes include:
Damage to the thyroid gland from
Previous thyroid surgery or thyroid treatment e.g. radioactive treatment
Iodine deficiency (This is the most common cause worldwide, but uncommon here in Ireland.)
Side effects of certain medications e.g. Lithium, Carbimazole, Amiodarone
Congenital (born with Hypothyroidism)
Pituitary Gland Dysfunction (The pituitary is part of the brain that controls the production of thyroid hormone)