Osteoarthritis occurs when the cartilage that cushions the ends of bones in your joints deteriorates over time. The smooth surface of the cartilage becomes rough, causing irritation. Eventually, if the cartilage wears down completely, you may be left with bone rubbing on bone â€” causing the ends of your bones to become damaged and your joints to become painful.
It isn't clear what causes osteoarthritis in most cases. Researchers suspect that it's a combination of factors, including being overweight, the aging process, joint injury or stress, heredity, and muscle weakness.
Osteoarthritis symptoms often develop slowly and worsen over time. Signs and symptoms of osteoarthritis include:
Pain in a joint during or after use, or after a period of inactivity
Tenderness in the joint when you apply light pressure
Stiffness in a joint, that may be most noticeable when you wake up in the morning or after a period of inactivity
Loss of flexibility may make it difficult to use the joint
Grating sensation when you use the joint
Bone spurs, which appear as hard lumps, may form around the affected joint
Swelling in some cases
Osteoarthritis symptoms most commonly affect the hands, hips, knees and spine.
Unless you've been injured or placed unusual stress on a joint, it's uncommon for osteoarthritis symptoms to affect your jaw, shoulder, elbows, wrists or ankles.