In majority of the arthritis there is more than one causative factor.
Degenerative arthritis (osteo-arthritis) is related to age, body weight, and injury.

        Rheumatic fever arthritis is preceded by infections with specific types of bacteria in the throat and upper respiratory tract. However, the bacteria themselves do not cause rheumatic fever arthritis but excite an abnormal immune response (usually concerned with defence mechanism of body) in the joints and sometimes in the heart and kidney as well.

        Uncommonly, bacteria can directly cause pyogenic arthritis. Several types of infections (for example urinary, diarrhoea, sexual diseases) can indirectly cause post-infective forms of arthritis.

In rheumatoid arthritis which is marked by multiple joint swellings and deformities the exact cause is not known, but hereditary and infections play an important role.

        Many of the spondylitic conditions associated with back pains are related to excess body weight, poor postures and injuries. Ankylosing spondylitis is an inflammatory disorder of the spine which is often seen in multiple male members of a family, and present with low back ache. Gout is caused by excess deposition of uric acid in joints.

        Though in many forms of arthritis the precise nature of initial attack to the joints is not known the subsequent sequence of events which produce damage to the joints and also make it chronic and progressive are now well known. And the latter has made the new therapeutic strategies more effective.