Table 3

Causes of hypothyroidism (in decreasing order of frequency)

Adult
Hashimoto's disease
131I therapy for hyperthyroidism
Subtotal thyroidectomy for hyperthyroidism or tumour
Previous antithyroid drug therapy
Postpartum (60%–70% transient)
Drugs (lithium, amiodarone, iodides interferon alfa)
Pituitary hypothyroidism (secondary)
Hypothalamic hypothyroidism (tertiary)
Subacute thyroiditis, silent thyroiditis
Iodine deficiency
Generalised resistance to thyroid hormone
Child/neonate
Neonatal hypothyroidism
 Thyroid agenesis
 Thyroid ectopia
 Thyroid dyshormonogenesis
 Others
Resistance to thyroid hormone
Isolated TSH deficiency