Your Anti-Aches & Pains Guide
Are You at Risk?
Not to be confused with rheumatoid arthritis (an autoimmune disorder), osteoarthritis is known as "wear-and-tear arthritis." It occurs when cartilage, a substance that cushions the ends of bones, becomes thin, damaged, or worn away, allowing bone to rub against bone. The result: pain and stiffness, particularly if you haven't used a joint for a few hours. An osteoarthritis sufferer's knees may hurt when she wakes up but then feel better as she moves around, says rheumatologist John H. Klippel, MD, president of the Arthritis Foundation, in Atlanta.
If you have osteoarthritis in your knee or hip (along with the hands, neck, and lower back, the most common places the disease strikes), you may notice stiffness when you stand after being seated for a while or when you've overused a joint -- for instance, after a long day shopping.
But not everyone with osteoarthritis develops pain, and doctors don't know why. Many people show signs of the disease on an X-ray without having suspected something was wrong. Nor do they know why some people are more susceptible than others. Age is a leading risk factor, as is genetics: Having a sibling with knee osteoarthritis may double your risk. People who have knee or hip osteoarthritis, Japanese researchers also recently discovered, have a mutation in a gene that affects cartilage.
You're also more likely to develop osteoarthritis if you've ever had a joint injury. Teenage female soccer players who had torn their anterior cruciate ligament (which helps hold the knee in place) showed signs of knee osteoarthritis as young as age 26, Swedish researchers recently found. Any repetitive joint usage makes us vulnerable. For instance, Chinese researchers found that regular chopstick users were more likely to develop osteoarthritis in the fingers of the hands that held the chopsticks than in their other hands.
Being overweight also puts enormous strain on joints and increases your risk. Obese women have nearly four times the risk of knee osteoarthritis as normal-weight women, according to data from the CDC's first National Health and Nutrition Examination Survey. Other research suggests that metabolic factors, such as hormones associated with obesity, also play a role in the disease.