Hypothyroidism Causes & Risks

Causes

Hashimoto's thyroiditis occurs when:

• Immune system produces antibodies that attack cells of the thyroid gland, causing chronic thyroid swelling and loss of function
• Other causes:
  • Idiopathic thyroid atrophy—destruction of thyroid tissue for unknown reasons
  • Iodine deficiency—when a thyroid gland needs iodine to produce thyroid hormone (rare in the US)
  • Subacute thyroiditis—following a viral upper respiratory tract infection
  • Medical treatments— radiation to the head and neck or surgical removal of part of the thyroid gland (called subtotal thyroidectomy )
  • Medications (eg, lithium , iodine, alpha-interferons, thiourea, amiodarone , interleukins)
  • Certain diseases (eg, cancer or infection)
  • Pituitary adenoma —benign tumor of the pituitary gland

Risk Factors

These factors increase your chance of developing hypothyroidism:

Risk factors include:

• Age: risk increases with age, especially over 65 years old
• Sex: more common in females
• Genetics: multiglandular autoimmune syndrome
• Ethnicity: Caucasian, Hispanic
• History of family members with hypothyroidism
• History of other autoimmune diseases:
  • Pernicious anemia
  • Type 1 diabetes
  • Underactive adrenal or parathyroid glands
  • Rheumatoid arthritis
  • Lupus

Tell your doctor if you have any of these risk factors.