Osteoarthritis (OA) should be suspected in patients with pain in the fingers, shoulders, hips, knees, or ankles, especially if they are older than 40 years. Patients older than 50 years who have joint pain, minimal morning stiffness, and functional impairment likely have OA. Radiography can confirm the diagnosis and may be helpful before surgical referral, but findings generally do not correlate well with symptoms. Exercise, physical therapy, knee taping, and tai chi are beneficial for knee OA. Medical therapy provides modest benefits in pain reduction and functional improvement; however, nonsteroidal anti-inflammatory drugs, tramadol, and other opioids have significant potential harms. Joint replacement may be considered for patients with moderate to severe pain and radiographically confirmed OA. Corticosteroid injections may be helpful in the short term. Vitamin D supplements, shoes specifically designed for persons with OA, antioxidant supplements, physical therapy for hip OA, ionized wrist bracelets, lateral wedge insoles for medial knee OA, and hyaluronic acid injections are not effective.