Explain what happens to the body with arthritis. What are risk factors?

One illness that goes hand in hand with aging is arthritis, a degenerative joint disease. There are more than 100 different types of arthritis; the most common is osteoarthritis, which affects joints that are injured by overuse, most commonly the hips, knees, lower back, and hands. The cartilage that protects the ends of bones where they meet at joints wears away and joints become less flexible and swell. Those who suffer from osteoarthritis experience a loss of movement and a great deal of pain. Aging is the most prominent risk factor for osteoarthritis; it often first appears in middle adulthood, occurring in about one third of adults ages 45-64, but becomes more common and worsens in severity during older adulthood. About half of adults aged 65 or older report a diagnosis of arthritis, and it is likely that many more cases remain undiagnosed. Nearly all older adults show at least some signs of osteoarthritis, but there are great individual differences. People whose job or leisure activities rely on repetitive movements are most likely to experience osteoarthritis. Office workers who type every day, for example, might experience osteoarthritis in their hands. Runners might experience it in their knees. Obesity can also be a cause as it places abnormal pressure on joints.