Osteoarthritis is the most common form of arthritis. It causes pain, swelling, and reduced motion in your joints. It can occur in any joint, but usually it affects your hands, knees, hips or spine.

Osteoarthritis breaks down the cartilage in your joints. Cartilage is the slippery tissue that covers the ends of bones in a joint. Healthy cartilage absorbs the shock of movement. When you lose cartilage, your bones rub together. Over time, this rubbing can permanently damage the joint.

Risk factors for osteoarthritis include

• Being overweight
• Getting older
• Injuring a joint

No single test can diagnose osteoarthritis. Most doctors use several methods, including medical history, a physical exam, x-rays, or lab tests.

Treatments include exercise, medicines, and sometimes surgery.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases