• Areflexia 796.1
  • Areola - see condition
  • Argentaffinoma (M8241/1) - see also Neoplasm, by site, uncertain behavior
  • Argentinian hemorrhagic fever 078.7
  • Arginosuccinicaciduria 270.6
  • Argonz-Del Castillo syndrome (nonpuerperal galactorrhea and amenorrhea) 253.1
  • Argyll-Robertson phenomenon, pupil, or syndrome (syphilitic) 094.89
  • Argyria, argyriasis NEC 985.8
  • Arhinencephaly 742.2
  • Arias-Stella phenomenon 621.30
  • Ariboflavinosis 266.0
  • Arizona enteritis 008.1
  • Arm - see condition
  • Armenian disease 277.31
  • Arnold-Chiari obstruction or syndrome (see also Spina bifida) 741.0
  • Arousals
  • Arrest, arrested
  • Arrhenoblastoma (M8630/1)
  • Arrhinencephaly 742.2
  • Arrhythmia (auricle) (cardiac) (cordis) (gallop rhythm) (juvenile) (nodal) (reflex) (sinus) (supraventricular) (transitory) (ventricle) 427.9
  • Arrillaga-Ayerza syndrome (pulmonary artery sclerosis with pulmonary hypertension) 416.0
  • Arsenical