- Canities (premature) 704.3
- Canker (mouth) (sore) 528.2
- Cannabinosis 504
- Canton fever 081.9
- Cap
- Capillariasis 127.5
- Capillary - see condition
- Caplan's syndrome 714.81
- Caplan-Colinet syndrome 714.81
- Capsule - see condition
- Capsulitis (joint) 726.90
- Caput
- Car sickness 994.6
- Carapata disease 087.1
- Carate - see Pinta
- Carbohydrate-deficient glycoprotein syndrome (CDGS) 271.8
- Carboxyhemoglobinemia 986
- Carbuncle 680.9
- Carbunculus (see also Carbuncle) 680.9
- Carcinoid (tumor) (M8240/1) - see Tumor, carcinoid
- Carcinoidosis 259.2
- Carcinoma (M8010/3) - see also Neoplasm, by site, malignant
