What Is Osteoarthritis? Osteoarthritis is a chronic joint condition where the protective cartilage wears down over time. This can cause symptoms like joint pain, stiffness, swelling, and difficulty moving. It often affects major joints such as the knees, hips, and hands. More Although there is no cure for osteoarthritis, treatment options and lifestyle changes like exercise and managing weight can help control symptoms. Over 32 million adults in the U.S. are diagnosed with osteoarthritis.