• OA [osteoarthritis]
  • Oat cell carcinoma
  • Obesity
  • Obesity hypoventilation
  • Obesity in adults
  • Obesity in children
  • Obsessive-compulsive disorder
  • Obstructive shock
  • Obstructive sleep apnea in adults
  • Obstructive sleep apnea in children
  • Obstructive uropathy
  • Occupational asthma
  • OCD [obsessive-compulsive disorder]
  • Oleander ingestion
  • Olecranon bursitis
  • Oligomenorrhea (evaluation of)
  • Omphalocele and gastroschisis
  • Ondine's curse
  • Onychomycosis
  • Open-angle glaucoma
  • Opiate abuse
  • Opioid overdose
  • Opioid use disorder
  • Optic neuritis
  • Optimizing functional status in the elderly
  • Oral candidiasis
  • Oral contraceptives
  • Oral leukoplakia
  • Oral mucositis
  • Oral thrush
  • Orbital cellulitis
  • Orbital fractures
  • Orchitis, epididymitis
  • Orchitis, mumps
  • Organophosphate poisoning
  • Oropharyngeal cancer
  • Oroya fever
  • Orthostatic hypotension
  • OSA [obstructive sleep apnea]
  • Osgood-Schlatter disease
  • Osteitis deformans
  • Osteoarthritis
  • Osteochondritis dissecans
  • Osteomalacia
  • Osteomyelitis
  • Osteoporosis
  • Osteoporotic spinal compression fractures
  • Osteosarcoma
  • Otic barotrauma
  • Otitis externa
  • Otitis media
  • Ovarian cancer
  • Ovarian cyst
  • Ovarian failure
  • Ovarian polycystic syndrome
  • Ovarian torsion
  • Overactive bladder
  • Overdose, BZD [benzodiazepine]
  • Overdose, crack cocaine
  • Overdose, heroin
  • Overdose, narcotic
  • Overdose, TCA [tricyclic antidepressant]
  • Overlap syndromes
  • Overview of acid-base and electrolyte disorders
  • Overview of acute coronary syndrome
  • Overview of brain tumors
  • Overview of chronic alcoholism
  • Overview of COPD
  • Overview of depression
  • Overview of dermatitis
  • Overview of diabetes
  • Overview of dysrhythmias
  • Overview of HIV
  • Overview of leukemia
  • Overview of meningitis
  • Overview of musculoskeletal pain
  • Overview of occupational overuse syndromes
  • Overview of pneumonia
  • Overview of pregnancy complications
  • Overview of seizure disorder
  • Overview of skin cancer
  • Overview of sport-related injuries
  • Overview of STDs
  • Overview of stroke
  • Overview of substance abuse and overdose
  • Overview of thyroid dysfunction
  • Overview of vertigo
  • Overweight, adult
  • Overweight, children
  • Oxalate ingestion, plant-based