Hashimoto’s Thyroiditis: This is an autoimmune disease. That is, the body’s immune system mistakenly attacks and destroys the thyroid gland. This is the most common cause of hypothyroidism.
Iodine deficiency: The body needs iodine to make thyroid hormone. A lack of iodine in the diet can affect the function of the gland (which is now very rare).
Surgery: If part or all of the gland has to be removed due to tumors or cancer in the thyroid gland, hormone production stops.
Radiation therapy: Radiation therapy to the area around the neck for cancer treatment can damage the thyroid gland.
Certain medications: Long-term use of certain mental health medications (e.g. Lithium) can slow down the function of the thyroid gland.
Congenital Hypothyroidism: Some children are born with a thyroid gland that is not properly developed. This is called ‘congenital hypothyroidism’.
Pituitary gland problems: The pituitary gland in the brain controls the thyroid gland. If there is a tumor or something else in the pituitary gland, the thyroid is not stimulated, which can cause hypothyroidism.
