- Congenital malformation
- Conization
- Conjunctivitis definition - Eye Disorders including cataracts, Lasik eye surgery, blindness, glaucoma and eye allergy
- Conjunctivitis, allergic
- Connective tissue
- Conor and Bruch disease
- Conn syndrome
- Consanguinity
- Conserved sequence
- Constipation
- Contig
- Contig map
- Contraceptive device, intrauterine (IUD)
- Contraction
- Contraction, uterine
- Contralateral
- Control (research)
- Contusion
- Co-payment
- Coronal
- Coronary artery bypass graft
- Corpora cavernosa
- Corpus
- Coryza
- Cosmid
- Costal margin
- Cortex
- Cortical
- Corticosteroid
- Cortisol
- Costochondritis
- Cough
- Cough suppressant
- Cousin marriage
- CPR
- Cracked tooth syndrome
- Cramp, writer's
- Cranial arteritis
- Cranial dystonia
- Craniopharyngioma