- Peritonitis
- Pheochromocytoma
- Phosphorus
- Phosphorus
- Pilonidal cyst
- Pinched nerve
- Pink eye (Conjunctivitis)
- Pituitary tumors
- Plague
- Plantar fasciitis
- Plantar warts
- Pleurisy
- Pneumococcal vaccination
- Pneumonia
- Pneumonitis
- Pneumothorax
- POEMS Syndrome
- Polycystic kidney disease
- Polycystic ovary syndrome
- Polycythemia vera