- Akureyri disease (epidemic neuromyasthenia) 049.8
- Alacrima (congenital) 743.65
- Alactasia (hereditary) 271.3
- Alagille syndrome 759.89
- Alalia 784.3
- Alaninemia 270.8
- Alastrim 050.1
- Albarrán's disease (colibacilluria) 791.9
- Albers-Schönberg's disease (marble bones) 756.52
- Albert's disease 726.71
- Albinism, albino (choroid) (cutaneous) (eye) (generalized) (isolated) (ocular) (oculocutaneous) (partial) 270.2
- Albinismus 270.2
- Albright (-Martin) (-Bantam) disease (pseudohypoparathyroidism) 275.49
- Albright (-McCune) (-Sternberg) syndrome (osteitis fibrosa disseminata) 756.59
- Albuminous - see Condition
- Albuminuria, albuminuric (acute) (chronic) (subacute) 791.0
- Albumosuria 791.0
- Alcaptonuria 270.2
- Alcohol, alcoholic
- Alcoholism 303.9
- Alder's anomaly or syndrome (leukocyte granulation anomaly) 288.2
- Alder-Reilly anomaly (leukocyte granulation) 288.2