- Protanomaly 368.51
- Protanopia (anomalous trichromat) (complete) (incomplete) 368.51
- Protection (against) (from) - see Prophylactic
- Protein
- Proteinemia 790.99
- Proteinosis
- Proteinuria (see also Albuminuria) 791.0
- Proteolysis, pathologic 286.6
- Protocoproporphyria 277.1
- Protoporphyria (erythrohepatic) (erythropoietic) 277.1
- Protrusio acetabuli 718.65
- Protrusion
- Proud flesh 701.5
- Prune belly (syndrome) 756.71
- Prurigo (ferox) (gravis) (Hebra's) (hebrae) (mitis) (simplex) 698.2
- Pruritus, pruritic 698.9
- Psammocarcinoma (M8140/3) - see Neoplasm, by site, malignant
- Pseudarthrosis, pseudoarthrosis (bone) 733.82
- Pseudo-Argyll-Robertson pupil 379.45
- Pseudo-Hurler's disease (mucolipidosis III) 272.7
- Pseudo-obstruction
- Pseudo-Turner's syndrome 759.89