• Arthrosis (deformans) (degenerative) (see also Osteoarthrosis) 715.9
  • Arthus phenomenon 995.21
  • Articular - see also condition
  • Articulation
  • Artificial
  • ARV (disease) (illness) (infection) - see Human immunodeficiency virus (disease) (illness) (infection)
  • Arytenoid - see condition
  • Asbestosis (occupational) 501
  • Asboe-Hansen's disease (incontinentia pigmenti) 757.33
  • ASC-H (atypical squamous cells cannot exclude high grade squamous intraepithelial lesion) 795.02
  • ASC-US (atypical squamous cells of undetermined significance) 795.01
  • Ascariasis (intestinal) (lung) 127.0
  • Ascaridiasis 127.0
  • Ascaridosis 127.0
  • Ascaris 127.0
  • Ascending - see condition
  • Aschoff's bodies (see also Myocarditis, rheumatic) 398.0
  • Ascites 789.5
  • Ascorbic acid (vitamin C) deficiency (scurvy) 267
  • ASCVD (arteriosclerotic cardiovascular disease) 429.2
  • Aseptic - see condition
  • Asherman's syndrome 621.5