- Contusion (skin surface intact) 924.9
- Conus (any type) (congenital) 743.57
- Convalescence (following) V66.9
- Conversion
- Converter, tuberculosis (test reaction) 795.5
- Convulsions (idiopathic) 780.39
- Convulsive - see also Convulsions
- Cooke-Apert-Gallais syndrome (adrenogenital) 255.2
- Cooley's anemia (erythroblastic) 282.49
- Coolie itch 126.9
- Cooper's
- Coordination disturbance 781.3
- Copper wire arteries, retina 362.13
- Copra itch 133.8
- Coprolith 560.39
- Coprophilia 302.89
- Coproporphyria, hereditary 277.1
- Coprostasis 560.39
- Cor
- Corbus' disease 607.1
- Cord - see also condition
- Cord's angiopathy (see also Tuberculosis) 017.3 [362.18]