Osteoarthritis (OA) is a degenerative joint disease primarily affecting cartilage and bone, leading to pain, stiffness, and decreased mobility, often in weight-bearing joints such as knees and hips. It is the most common form of arthritis, particularly prevalent in older individuals, with risk factors including age, obesity, and history of joint injury. Diagnosis involves clinical evaluation and imaging, while treatment focuses on symptom management and may include pharmacological and non-pharmacological approaches, including lifestyle changes and possible surgical interventions.