- Concato's disease (pericardial polyserositis) 423.2
- Concavity, chest wall 738.3
- Concealed
- Concentric fading 368.12
- Concern (normal) about sick person in family V61.49
- Concrescence (teeth) 520.2
- Concretio cordis 423.1
- Concretion - see also Calculus
- Concussion (current) 850.9
- Condition - see also Disease
- Conduct disturbance (see also Disturbance, conduct) 312.9
- Condyloma NEC 078.11
- Confinement - see Delivery
- Conflagration - see also Burn, by site
- Conflict
- Confluent - see condition
- Confusion, confused (mental) (state) (see also State, confusional) 298.9
- Confusional arousals 327.41
- Congelation 991.9
- Congenital - see also condition
- Congestion, congestive
- Congestive - see Congestion