Subclinical Thyroid Disease

Abnormal TSH with normal thyroid hormone

Subclinical hypothyroidism

  • ↑TSH, normal fT4/3
  • Risk of progression to overt hypothyroidism
  • Higher risk if strongly TPO antibody positive
  • Treatment generally advised if TSH > 10
  • Always treat in pregnancy to maintain normal TSH

Subclinical hyperthyroidism

  • ↓TSH, normal fT4/3
  • Risk of progression to overt hyperthyroidism
  • Often seen in multinodular goitre
  • Association with osteoporosis and atrial fibrillation
  • Treatment generally advised if TSH <0.1% (or if co-existing osteoporosis/fracture or AF)