- Circulation, fetal
- Circulatory
- Circulatory system
- Circumcision
- Cirrhosis
- Civilian Health and Medical Program of the Uniform
- Cl (chloride)
- Clap
- Clamydia
- Clasped thumbs and mental retardation
- Clavicle
- Cleft uvula
- Click-murmur syndrome
- Clinical cytogenetics
- Clinical disease definition - Diabetes Mellitus, Type 2, Type 1, and Metabolic Disorders treatment and medications
- Clinical research trials
- Clinical trials
- Clitoris
- Clone
- Clone bank
- Cloning
- Cloning, cell
- Cloning, DNA
- Clones, recombinant
- Clostridium difficile
- Clot-dissolving medication
- Clubfoot
- cM
- CME
- CNS (central nervous system)
- CNS prophylaxis
- Cocci
- Coccus
- Coccyx
- Code
- Codon
- Coefficient of inbreeding
- Cohort
- Coinsurance
- Colchicine