- Hippus 379.49
- Hirschfeld's disease (acute diabetes mellitus) (see also Diabetes) 250.0
- Hirschsprung's disease or megacolon (congenital) 751.3
- Hirsuties (see also Hypertrichosis) 704.1
- Hirsutism (see also Hypertrichosis) 704.1
- Hirudiniasis (external) (internal) 134.2
- His-Werner disease (trench fever) 083.1
- Hiss-Russell dysentery 004.1
- Histamine cephalgia 346.2
- Histidinemia 270.5
- Histidinuria 270.5
- Histiocytic syndromes 288.4
- Histiocytoma (M8832/0) - see also Neoplasm, skin, benign
- Histiocytosis (acute) (chronic) (subacute) 277.89
- Histoplasmosis 115.90
- History (personal) of
- HIV infection (disease) (illness) - see Human immunodeficiency virus (disease) (illness) (infection)
- Hives (bold) (see also Urticaria) 708.9
- Hoarseness 784.49
- Hobnail liver - see Cirrhosis, portal
- Hobo, hoboism V60.0
- Hodgkin's
