1. Osteoarthritis is the most common joint-related condition in the United States, affecting more than 40 million people.

2. 80 percent of people with osteoarthritis are over age 55.

3. Osteoarthritis is most often due to wear and tear on the joints due to age, excess weight, or repetitive stress.

4. Rheumatoid arthritis affects more than two million Americans and frequently begins in middle age.

5. While rheumatoid arthritis can occur anytime, 70 percent of cases are diagnosed between ages 30 and 70, often peaking in a person’s 40s.

6. Unlike osteoarthritis, rheumatoid arthritis is caused by an autoimmune disease.

7. Cartilage is the rubbery tissue that covers the ends of your bones and acts like a shock absorber where your bones meet.

8. You have cartilage at your hip joints, knees, elbows, fingers, wrists, ankles, shoulders, neck, toes, jaw, and between your vertebrae.

9. Collagen fibers give cartilage its strength and structural integrity.

10. Proteoglycans are proteins linked to glycosaminoglycans—GAGs—that bind to the water that lubricates your joints.