causes

Hypothyroidism affects around 1-2% of women in the UK and is around 5-10 times more common in females than males.

Primary hypothyroidism

Hashimoto's thyroiditis

• most common cause
• autoimmune disease, associated with IDDM, Addison's or pernicious anaemia
• may cause transient thyrotoxicosis in the acute phase
• 5-10 times more common in women

Subacute thyroiditis (de Quervain's)

• painful and tender thyroid

Riedel thyroiditis

After thyroidectomy or radioiodine treatment

Drug therapy (e.g. lithium, amiodarone or anti-thyroid drugs such as carbimazole)

Dietary iodine deficiency

Secondary hypothyroidism (rare)

From pituitary failure

Other associated conditions

• Down's syndrome
• Turner's syndrome