- Lutz-Splendore-de Almeida disease (Brazilian blastomycosis) 116.1
- Luxatio
- Luxation - see also Dislocation, by site
- Lycanthropy (see also Psychosis) 298.9
- Lyell's disease or syndrome (toxic epidermal necrolysis) 695.1
- Lyme disease 088.81
- Lymph
- Lymph-hemangioma (M9120/0) - see Hemangioma, by site
- Lymphadenitis 289.3
- Lymphadenoid goiter 245.2
- Lymphadenopathy (general) 785.6
- Lymphadenopathy-associated virus (disease) (illness) (infection) - see Human immunodeficiency virus (disease) (illness) (infection)
- Lymphadenosis 785.6
- Lymphangiectasis 457.1
- Lymphangiectatic elephantiasis, nonfilarial 457.1
- Lymphangioendothelioma (M9170/0) 228.1
- Lymphangioma (M9170/0) 228.1
- Lymphangiomyoma (M9174/0) 228.1
- Lymphangiomyomatosis (M9174/1) - see Neoplasm, connective tissue, uncertain behavior
- Lymphangiosarcoma (M9170/3) - see Neoplasm, connective tissue, malignant
- Lymphangitis 457.2
- Lymphatic (vessel) - see condition
