Arthritis and arthrosis are very common connective tissue diseases. In arthritis, the problem is an inflammation of the bones, joints, and tendons. Chronic arthritis can lead to arthrosis, a degradation of cartilage in the joints. The cartilage can lose its elasticity, become rough and lose mass. This can result in the deformation of the cartilage. Both arthritis and arthrosis are very painful diseases, with all the typical symptoms of inflammation, including fever, reddening, and swelling. Joints may also become stiff.