- Paget disease of the bone
- Painful papillae of the tongue
- Paget disease of the nipple (rare breast cancer)
- Pallister Killian syndrome (rare inherited disorder)
- Pancreas inflammation (pancreatitis, chronic)
- Pancoast syndrome (apical lung tumor)
- Pancreatic cancer (tumor)
- Pancreatitis (pancreas inflammation)
- Panhypopituitarism (pituitary gland malfunction)
- Pancytopenia
- Panic disorder
- Paralytic Ileus (intestinal paralysis)
- Paraphimosis
- Parasite infections
- Parathyroid cancer
- Parkinson's disease (movement disorder)
- Paronychia (infection around the nail)
- Parotitis (salivary gland inflammation)
- PCP (phencyclidine abuse)
- Patellar dislocation (knee cap dislocation)
- Pelvic inflammatory disease (PID, female reproductive organ infection)
- Pemphigoid
- Pemphigus (rare skin disorder)
- Penis carcinoma (tumor)
- Pepto Bismol or Kaopectate ingestion (bismuth)
- Pericarditis (heart sac inflammation)
- Perforated septum (hole in skin between nostrils)
- Pericoronitis
- Periodontitis (gum inflammation)
- Periorbital cellulitis (infection around eye)
- Peripheral neuropathy (nerve damage)
- Peripheral nerve transection (nerve injury)
- Peripheral vascular disease (blocked blood vessels)
- Peritonsillar abscess (collection of pus around tonsils)
- Peritonitis (abdominal cavity inflammation)
- Pernicious anemia (vitamin deficiency blood disorder)
- Personality disorder (unhealthy patterns of thinking and behavior)
- Pesticide poisoning (organophosphate poisoning)
- Peyronie's disease (abnormal curvature of the penis)
- Pharyngeal pouch (Zenker's diverticulum, weakening of the esophageal wall)
- Peyote abuse (mescaline abuse)
- Pharyngitis (throat infection)
- Phenylketonuria (PKU)
- Pheochromocytoma (adrenal gland tumor)
- Phimosis
- Pickwickian syndrome (severe obesity)
- Phobias (irrational fear)
- Pilonidal cyst (fluid filled sac on tailbone)
- Pinguecula (growth on the eye)
- Pituitary tumor
- Pinworms (common intestinal worm)
- Placenta previa (placenta covers cervix)
- Pityriasis rosea (inflammatory skin rash)
- Placental abruption (placenta separation)
- Plague (bubonic plague, bacteria yersinia infection)
- Plantar fasciitis (inflammation of tissue at the bottom of the foot)
- Plantar wart (human papilloma virus infection, foot warts)
- Pleural effusion (abnormal chest fluid)
- Pleuritis (inflammation of the lung's lining, pleurisy)
- Pneumoconiosis (lung disease)
- Pneumocystis pneumonia (PCP, fungal lung infection)
- Pneumonia (lung infection)
- Pneumothorax (collapse of lung)
- Poison ivy (poison oak, poison sumac)
- Polyarteritis Nodosa (PAN)
- Poliomyelitis (polio)
- Poisoning
- Polycystic ovarian syndrome (PCOS, female hormonal disorder)
- Polycystic kidney disease (inherited kidney disorder)
- Polymyalgia rheumatica (PMR, muscle and joint disorder)
- Polycythemia vera (increased number of red blood cells)
- Polymyositis (muscle inflammation)
- Polyphagia (overeating)
- Porphyria (rare disorder of skin, nervous system)
- Post concussive syndrome (symptoms after a concussion)
- Post herpetic neuralgia (nerve pain after shingles)
- Post nasal drip
- Post-polio syndrome
- Post-traumatic stress disorder (PTSD)
- Posterior vitreous detachment (common eye abnormality)
- Postural hypotension (low blood pressure after standing)
- Prediabetes (high blood sugar)
- Preeclampsia (toxemia of pregnancy)
- Pregnancy tumor
- Premature ejaculation
- Premenstrual dysphoric disorder (PMDD)
- Premenstrual syndrome (PMS)
- Presbyopia (aging vision)
- Prescription drug abuse
- Preseptal hematoma (blood clot in the nose)
- Priapism (persistent erection)
- Primary affective disorder (depression)
- Primary dysmenorrhea (painful menstruation)
- Primary sclerosing cholangitis (bile duct disease)
- Prinzmetal angina (heart artery spasm)
- Prostate cancer (male anatomy cancer)
- Prostatitis (prostate inflammation)
- Pruritus ani (anal itching)
- Pseudogout (calcium deposit arthritis)
- Pseudomonas infection
- Pseudotumor cerebri (increased pressure in the skull)
- Psoriasis (scaly skin disease)
- Psoriatic arthritis (joint pain and stiffness)
- Psychosis
- Pubic lice
- Puerperal depression (depression after giving birth)
- Pterygium (growth on the eye)
- Pulmonary edema (fluid build-up in the lungs)
- Puerperal psychosis (loss of contact with reality after birth)
- Pulmonary embolism (blood clot in the lungs)
- Pulmonary fibrosis (lung scarring)
- Pulmonary hypertension (high blood pressure in the lungs)
- Pulpitis (dental root inflammation)
- Puncture wound
- Puncture wound, ankle
- Puncture wound, arm
- Puncture wound, ear
- Puncture wound, eyelid
- Puncture wound, face
- Puncture wound, finger
- Puncture wound, foot
- Puncture wound, hand
- Puncture wound, knee
- Puncture wound, leg
- Puncture wound, lip
- Puncture wound, mouth
- Puncture wound, scalp
- Puncture wound, skin
- Puncture wound, toe
- Pyelonephritis (kidney infection)
- Pyomyositis (muscle infection)