- H disease 270.0
- H.E.L.L.P 642.5
- Haas' disease (osteochondrosis head of humerus) 732.3
- Habermann's disease (acute parapsoriasis varioliformis) 696.2
- Habit, habituation
- Hadfield-Clarke syndrome (pancreatic infantilism) 577.8
- Haff disease 985.1
- Hag teeth, tooth 524.39
- Hageman factor defect, deficiency, or disease (see also Defect, coagulation) 286.3
- Haglund's disease (osteochondrosis os tibiale externum) 732.5
- Haglund-Läwen-Fründ syndrome 717.89
- Hagner's disease (hypertrophic pulmonary osteoarthropathy) 731.2
- Hailey-Hailey disease (benign familial chronic pemphigus) 757.39
- Hair - see also condition
- Hairball in stomach 935.2
- Hairy black tongue 529.3
- Half vertebra 756.14
- Halitosis 784.99
- Hallermann-Streiff syndrome 756.0
- Hallervorden-Spatz disease or syndrome 333.0
- Hallopeau's
- Hallucination (auditory) (gustatory) (olfactory) (tactile) 780.1