Osteoarthritis is a slow, progressive disease. Cartilage gradually breaks down until the bones, which were once separated by cartilage, begin to rub against each other.

The rate at which osteoarthritis progresses varies widely from person to person. Symptoms may not develop for years, until bones and tissues become damaged. It is hard to predict the course of osteoarthritis, as symptoms may stop for periods of time. Joint symptoms may either remain constant or gradually get worse over several years. You may have symptoms that come and go (flares), as you would with other forms of arthritis.

Although the disease process of osteoarthritis affects joint cartilage throughout the body, you most likely will have symptoms in only one or two joints or groups of joints. Symptoms most often affect the spine, fingers, hips, knees, or toes. At first, pain may occur only when you are active. As the disease progresses, pain may also occur when you are resting.

Bones in the finger joints may enlarge, developing bumps known as Heberden's and Bouchard's nodes.

Bowleg and knock-knee alignments of the knees are common in osteoarthritis. These misalignments result in uneven cartilage loss and, as the cartilage wears down, the bowleg or knock-knee condition becomes even worse.

Many people can manage their osteoarthritis symptoms with medicine and lifestyle changes, although there is no cure for the condition. In a few people, osteoarthritis becomes severe enough to require surgery to replace the worn joint or fuse the bones together so that the joint will not bend. Surgical techniques and the artificial joint parts used for the surgeries are constantly improving.

Learn about the complications of osteoarthritis.