• Ophiasis 704.01
  • Ophthalmia (see also Conjunctivitis) 372.30
  • Ophthalmitis - see Ophthalmia
  • Ophthalmocele (congenital) 743.66
  • Ophthalmoneuromyelitis 341.0
  • Ophthalmopathy, infiltrative with thyrotoxicosis 242.0
  • Ophthalmoplegia (see also Strabismus) 378.9
  • Opisthognathism 524.00
  • Opisthorchiasis (felineus) (tenuicollis) (viverrini) 121.0
  • Opisthotonos, opisthotonus 781.0
  • Opitz's disease (congestive splenomegaly) 289.51
  • Opiumism (see also Dependence) 304.0
  • Oppenheim's disease 358.8
  • Oppenheim-Urbach disease or syndrome (necrobiosis lipoidica diabeticorum) 250.8 [709.3]
  • Opsoclonia 379.59
  • Optic nerve - see condition
  • Orbit - see condition
  • Orchioblastoma (M9071/3) 186.9
  • Orchitis (nonspecific) (septic) 604.90
  • Orf 051.2
  • Organic - see also condition
  • Oriental