People who have a family history of thyroid problems are more at risk of developing one, and women over the age of 60 are also at an increased risk. Certain illnesses including pernicious anemia and type 1 diabetes also put a person at a higher risk of developing thyroid disease.Thyroid hormone abnormalities can occur due to Hashimoto's thyroiditis, the most common cause of hypothyroidism; Graves' disease; medications such as lithium or amiodarone; iodine deficiency or excess (not commonly seen in the United States); and pituitary gland abnormalities. Thyroid cancer is more common in patients with a previous history of head and neck radiation.