While there are over 100 different arthritis-related conditions, half of the 46 million sufferers in the U.S. have osteoarthritis. In fact, it's estimated that almost 50% of us will be dealing with some form of it by the time we turn 65. The first signs are typically puffy or swollen knees and legs that hurt when straightened or bent. The pain is caused by bone rubbing on bone after cartilage (which acts as a cushion) has broken down. Early symptoms are often attributed to general muscle soreness. "People need to zero in on the pain they're feeling," says Lisa Mandl, M.D., a rheumatologist at the Hospital for Special Surgery, an orthopedic hospital in New York City. "With arthritis, you'll have pain in certain pivot points—like your knees and hips—and less in the surrounding muscle tissue." Plus, muscle aches go away in a few days and feel better with rest and massage; arthritis pain doesn't.
Women between the ages of 25 and 50 are also prone to another form of arthritis: rheumatoid. This condition occurs when the body's immune system mistakenly attacks healthy tissue in the joints, eating up cartilage and bone. While osteoarthritis damages large joints, rheumatoid first targets smaller ones in the wrists, hands, ankles, and feet—causing stiffness, pain, redness and swelling (especially in the mornings). The joints may feel warm and many sufferers experience low-grade fevers, fatigue, and weight loss. As this autoimmune disease progresses, it can spread throughout the body, eventually affecting larger joints and damaging organs like the heart and lungs.