Osteoarthritis (OA) is a chronic, degenerative joint disease characterized by cartilage loss, joint space narrowing, osteophyte formation, and subchondral changes. It typically affects older adults and commonly involves the knees, hips, hands, and spine. Risk factors include age, female sex, obesity, joint injury, and genetics. Clinical features include joint pain worsened by activity, morning stiffness lasting under 30 minutes, crepitus, and reduced range of motion. Diagnosis is primarily clinical, supported by imaging if necessary. Management includes patient education, exercise, weight management, topical/oral analgesics, and in severe cases, intra-articular injections or surgery. Individualized, multidisciplinary care is essential for optimal outcomes.