Overstrain: High stress / overloading on a joint, as in top-level sports, can in time increase wear on the cartilage. Equally, joint malformations (such as bandy legs or knock knees) can overload individual parts of a joint and lead to arthritis. Also, excess weight can overload / overstrain the joints and so accelerate the process of arthritis; this applies especially to the hip and knee joints, which in any case bear heavy loads.

Injuries: Sports injuries are a common cause of arthritis. They do not have to be direct injuries to the cartilage tissue. For instance, in many cases, if a joint has been left unstable because of a torn cruciate ligament, there is now more friction between the bones forming the joint and arthritis is therefore pre-programmed. It is much the same with injuries to the meniscus, which is an important buffer in the knee; loss of the meniscus can lead to massive damage to the joint cartilage.

Advancing age: Like most bodily structures, the cartilage is subject to the natural processes of aging. The tissue becomes more brittle, its water content declines, and it becomes less resistant. Therefore, in many people increased wear in the joint cartilage becomes evident with advancing age.

Hereditary causes: Genetic causes play a large part in some kinds of arthritis. One example is Heberden’s nodes, which occur at the distal interphalangeal joints (end joints) of the fingers and typically run in families.

Rheumatic diseases: Autoimmune diseases, such as rheumatoid arthritis, can, like many other rheumatic diseases, cause joint inflammations, and these often lead to massive damage to cartilage and/or joints.

Other causes: Metabolic disorders (gout), bacterial inflammation of the joints, etc.