Subcategories

• Obstructive sleep apnea
• Osteoarthritis
• Occupational asthma
• Obesity
• Obesity, childhood
• Obsessive-compulsive disorder (OCD)
• Obsessive-compulsive personality disorder
• Obstetric cholestasis
• OCD
• Ocular albinism
• Ocular melanoma
• Ocular rosacea
• Oculocutaneous albinism
• ODD
• Oppositional defiant disorder (ODD)
• OHSS
• Ovarian hyperstimulation syndrome
• Onychomycosis
• Optic neuritis
• Oral cancer
• Oral candidiasis
• Oral thrush
• Oral lichen planus
• Orchitis
• Orophayrngeal cancer
• Orthostatic hypotension
• Orthostatic hypotension (postural hypotension)
• Osgood-Schlatter disease
• Osteoarthritis, cervical
• Osteochondritis dissecans
• Osteomalacia
• Osteomyelitis
• Osteonecrosis
• Osteophytes
• Osteoporosis
• Otitis externa
• Outer ear infection
• Otitis media
• Ovarian cancer
• Ovarian cysts
• Overactive bladder
• Overactive thyroid
• Oxyphil cell carcinoma