The joint pain of OA typically is described as being exacerbated by activity and relieved by rest. More advanced OA can cause pain at rest and during the night, leading to loss of sleep that further exacerbates pain. The cardinal symptoms that suggest a diagnosis of OA include Pain (typically described as activity related or mechanical; may occur with rest in advanced disease; often deep, aching, and not well localized; usually of insidious onset).

• Reduced function
• Stiffness (of short duration, also termed ‘‘gelling,’’ that is, short-lived stiffness after inactivity)
• Joint instability, buckling, or giving way
• Patients also may complain of reduced movement, deformity, swelling in the absence of systemic features such as fever, crepitus, discomfort associated with increased age (OA is unusual before age 40 years), and, when pain persists, pain-related psychologic distress.¹³