- Infants, healthy liveborn - see Newborn
- Infarct, infarction
- Infecting - see condition
- Infection, infected, infective (opportunistic) 136.9
- Infective, infectious - see condition
- Inferiority complex 301.9
- Infertility
- Infestation 134.9
- Infiltrate, infiltration
- Infirmity 799.89
- Inflammation, inflamed, inflammatory (with exudation)
- Inflation, lung imperfect (newborn) 770.5
- Influenza, influenzal 487.1
- Influenza-like disease (see also Influenza) 487.1
- Infraction, Freiberg's (metatarsal head) 732.5
- Infraeruption, teeth 524.34
- Infusion complication, misadventure, or reaction - see Complication, infusion
- Ingestion
- Ingrowing
- Inguinal - see also condition
- Inhalation
- Inhibition, inhibited
