Osteoarthritis affects more people than any other type. Physicians may refer to it as degenerative joint disease. Patient usually know this disease best as old age arthritis,
Why does osteoarthritis occur? In a normal joint a smooth elastic material called cartilage covers the ends of your bones where they meet. Cartilage enables the bones to glide smoothly across each other and gives joints their flexibility.

When the cartilage wears away, it becomes painful to move the joint. The ends of the bones may develop spurs, or outgrowths, and ligaments and membranes around the bones may thicken. As a result the shape and structure of the joint may change. In reaction to the pain, muscles near the joint may become tense and contract. As muscles weaken, use of the joint may become more restricted. While each case of osteoarthritis is different, your understanding should begin with the anatomy of bones and joints.

While osteoarthritis can occur in any joint, the joints most commonly affected are the weight-bearing ones: knees, hips, and lumbar spine. It often affects the joints of the fingers, the base of the thumb, and the big toe.

Physicians categorize cases of osteoarthritis as primary and secondary. The primary form seems to begin by itself, with no specific cause, while the secondary type may have many causes but often results from too much stress and strain on a joint. Primary osteoarthritis occurs mostly in women and may have a hereditary component because it seems to appear more in some families than in others. It sometimes begins fairly early in life, even during the late thirties and early forties. Osteoarthritis seems to be quite generalized and affects small joints such as the fingers and toes.