- Prothrombinase
- Proto oncogenes
- Protoanemonin
- Protocadherin
- Protocatechuic acid
- Protomers
- Proton ATPase
- Proton exchange membrane
- Proton gradient
- Proton induced x ray emission
- Proton motive force
- Proton pump
- Proton pump inhibitors
- Proton pumps
- Proton therapy
- Proton-coupled folate transporter
- Proton-transfer-reaction mass spectrometry
- Protonation
- Protonophore
- Protopanaxadiol
- Protopanaxatriol
- Protopine
- Protoplasm
- Protoplast
- Protoporphyrin
- Protoporphyrinogen IX
- Protothecosis
- Prototype drug
- Prototype theory
- Protoxin
- Protozoa
- Protozoal infection
- Protozoan
- Protriptyline
- Protrusio acetabuli
- Providencia
- Providencia stuartii
- Proviruses
- Provitamin
- Provocation test
- Prox1
- Proxalutamide
- Proxemics
- Proximal convoluted tubule
- Proximal femoral focal deficiency
- Proximal femur
- Proximal humerus fractures
- Proximal phalanx
- Proximal radioulnar joint
- Proximal subungual onychomycosis
- Proximal tubule
- Proximal tubules
- Proximity labeling
- Prucalopride
- Prunasin
- Prune Belly Syndrome
- Prunella
- Prunella vulgaris
- Prunes
- Prunus dulcis
- Prurigo
- Prurigo nodularis
- Prurigo pigmentosa
- Pruritic urticarial papules and plaques of pregnancy
- Pruritus
- Pruritus ani
- Pruritus vulvae
- Prussak's space
- Prussian blue
- Psalmotoxin
- Psammoma body
- Pseudarthrosis
- Pseudo-Cushing's syndrome
- Pseudoachondroplasia
- Pseudoallergy
- Pseudoaneurysms
- Pseudoangiomatous stromal hyperplasia
- Pseudoathetosis
- Pseudoautosomal region
- Pseudobulbar affect
- Pseudobulbar palsy
- Pseudocysts
- Pseudodementia
- Pseudodominance
- Pseudoenzymes
- Pseudoephedrine
- Pseudoexfoliation syndrome
- Pseudofolliculitis barbae
- Pseudogenes
- Pseudogout
- Pseudohermaphroditism
- Pseudohyperaldosteronism
- Pseudohypertrophy
- Pseudohypoaldosteronism
- Pseudohyponatremia
- Pseudohypoparathyroidism
- Pseudohypoxia
- Pseudokinase
- Pseudoknots
- Pseudolikelihood
- Pseudolymphoma
- Pseudomembranous colitis
- Pseudomembranous enterocolitis
- Pseudomeningocele
- Pseudomonadales
- Pseudomonas
- Pseudomonas aeruginosa
- Pseudomonas exotoxin
- Pseudomonas putida
- Pseudomonas stutzeri
- Pseudomyopia
- Pseudomyxoma peritonei
- Pseudonymization
- Pseudophakia
- Pseudopodia
- Pseudopregnancy
- Pseudopseudohypoparathyroidism
- Pseudopterygium
- Pseudorabies
- Pseudoreplication
- Pseudostellaria heterophylla
- Pseudostratified
- Pseudostratified columnar epithelium
- Pseudothrombocytopenia
- Pseudotyping
- Pseudouridine
- Pseudoxanthoma elasticum
- Psilocin
- Psilocybe
- Psilocybe cubensis
- Psilocybe mexicana
- Psilocybin
- Psilocybin mushrooms
- Psilocybine
- Psittacosis
- Psoas abscess
- Psoas major
- Psoas major muscle
- Psoas muscle
- Psoas sign
- Psoralen
- Psoriasis
- Psoriasis Area and Severity Index
- Psoriasis vulgaris
- Psoriatic arthritis
- Psoriatic erythroderma
- Psoroptes cuniculi
- Psoroptic mange
- Psyche
- Psychedelia