- Lacunar skull 756.0
- Laennec's cirrhosis (alcoholic) 571.2
- Lafora's disease 333.2
- Lag, lid (nervous) 374.41
- Lagleyze-von Hippel disease (retinocerebral angiomatosis) 759.6
- Lagophthalmos (eyelid) (nervous) 374.20
- Lahore sore 085.1
- Lakes, venous (cerebral) 437.8
- Laki-Lorand factor deficiency (see also Defect, coagulation) 286.3
- Lalling 307.9
- Lambliasis 007.1
- Lame back 724.5
- Lancereaux's diabetes (diabetes mellitus with marked emaciation) 250.8 [261]
- Landau-Kleffner syndrome 345.8
- Landouzy-Déjérine dystrophy (fascioscapulohumeral atrophy) 359.1
- Landry's disease or paralysis 357.0
- Landry-Guillain-Barré syndrome 357.0
- Lane's
- Langdon Down's syndrome (mongolism) 758.0
- Language abolition 784.69
- Lanugo (persistent) 757.4
- Laparoscopic surgical procedure converted to open procedure V64.41