- Aschoff's bodies (see also Myocarditis, rheumatic) 398.0
- Ascites 789.59
- Ascorbic acid (vitamin C) deficiency (scurvy) 267
- ASCVD (arteriosclerotic cardiovascular disease) 429.2
- Aseptic - see condition
- Asherman's syndrome 621.5
- Asialia 527.7
- Asiatic cholera (see also Cholera) 001.9
- Asocial personality or trends 301.7
- Asomatognosia 781.8
- Aspergillosis 117.3
- Aspergillus (flavus) (fumigatus) (infection) (terreus) 117.3
- Aspermatogenesis 606.0
- Aspermia (testis) 606.0
- Asphyxia, asphyxiation (by) 799.01
- Aspiration
- Asplenia 759.0
- Assam fever 085.0
- Assimilation, pelvis
- Assmann's focus (see also Tuberculosis) 011.0
- Astasia (-abasia) 307.9
- Asteatosis 706.8
