- Caisson disease, see Air, pressure, change
- Campfire (exposure to) (controlled), see Exposure, fire, controlled, not in building
- Capital punishment (any means), see Legal, intervention
- Car sickness, T75.3
- Casualty NEC (not due to war), X58
- Cat,
- Cataclysm, cataclysmic NEC (any injury), see Forces of nature
- Catching fire, see Exposure, fire
- Caught,
- Cave-in caused by cataclysmic earth surface movement or eruption, see Landslide
- Change in air pressure (s), see Air, pressure, change
- Choked, choking (on) (any object except food or vomitus),
- Civil insurrection, see War operations
- Cloudburst (any injury), X37.8
- Cold, exposure to NEC (accidental) (excessive) (extreme) (natural) (place), see Exposure, cold
- Collapse,
- Collision NEC (accidental), see Accident, transportV89.9
- Combustion, spontaneous, see Ignition
- Complication (delayed) of or following (medical or surgical procedure), Y84.9
- Compression,
- Conflagration, see Exposure, fire, uncontrolled
- Constriction (external),
- Contact (accidental),
- Coup de soleil, X32
- Crash,
- Cruelty (mental) (physical) (sexual), X58
- Crushed (accidentally), X58
- Cut, cutting (any part of body) (accidental), see Contact, with, by object or machine
- Cyclone (any injury), X37.1