- Potain's disease (pulmonary edema) 514
- Potain's syndrome (gastrectasis with dyspepsia) 536.1
- Pott's
- Potter's
- Pouch
- Poulet's disease 714.2
- Poultrymen's itch 133.8
- Poverty V60.2
- Prader-Labhart-Willi-Fanconi syndrome (hypogenital dystrophy with diabetic tendency) 759.81
- Prader-Willi syndrome (hypogenital dystrophy with diabetic tendency) 759.81
- Pre-AIDS - see Human immunodeficiency virus (disease) (illness) (infection)
- Pre-eclampsia (mild) 642.4
- Pre-syncope 780.2
- Preachers' voice 784.49
- Preauricular appendage 744.1
- Prebetalipoproteinemia (acquired) (essential) (familial) (hereditary) (primary) (secondary) 272.1
- Precipitate labor 661.3
- Preclimacteric bleeding 627.0
- Precocious
- Precocity, sexual (constitutional) (cryptogenic) (female) (idiopathic) (male) NEC 259.1
- Precordial pain 786.51
- Predeciduous teeth 520.2