- Cardiomyopathy, Hypertrophic
- Cellulitis
- Cerebral Hemorrhage
- Cerebrospinal Fluid Rhinorrhea
- Cerumen
- Cesarean Section
- Chickenpox
- Child Nutrition Disorders
- Chills
- Cholera
- Chronic Disease
- Chronic Pain
- Common Cold
- Community-Acquired Infections
- Complex Regional Pain Syndromes
- Conjunctivitis
- Conjunctivitis, Bacterial
- Constipation
- Contraception
- Cough
- Critical Illness
- Croup
- Cystic Fibrosis