Knee arthritis is one of the most common causes of knee pain and can refer to any of several different types of arthritis in the knee joint, of which the most common is probably osteoarthritis. This type of arthritis is caused by progressive wearing down of the cartilage in the joint, exposing the bone. Another common type of arthritis is rheumatoid arthritis.Contributory factors are age, being overweight and genetics. Pain, stiffness, swelling, tenderness and even a feeling that the knee may “give out” are all typical symptoms of the condition. Individuals diagnosed with this condition should consider the products below for relief of the discomfort it causes, but the advice of a doctor should always be the first step.