Osteoarthritis is the most common joint condition throughout the world. Though it is certainly associated with aging, symptoms and signs can develop in the 30s and 40s. The lower back and neck are commonly involved, however, weight-bearing joints and certain finger joints are often areas of significant problems. The primary issue with osteoarthritis is the gradual loss of cartilage, the "spacer" between bones. This process can similarly involve the disk spaces between individual bones of the back (vertebrae). As the cartilage gradually thins, the shape of the surrounding bones changes with enlargement of the bone as well as the potential development of prominences commonly known as spurs. There may be associated secondary changes of inflammation that can add to the symptoms and findings. There is no known cause for primary osteoarthritis. A variety of conditions may lead to secondary cartilage changes. Obesity is a major risk factor for osteoarthritis of the knees and hips. Findings on examination or seen on x-ray do not necessarily correlate with complaints. Indeed, a number of aging adults will have x-ray findings and have no symptoms in the area whatsoever. Treatment is directed at managing symptoms as well as exercises to maintain flexibility and improve strength. It is important to distinguish osteoarthritis from other joint conditions as the treatments are vastly different.