The primary cause of osteoarthritis is increasing body weight and increasing age. Apart from ageing, overweight and obesity are the main causes of osteoarthritis. The load to the knee joints, for example, is as much as four times of one’s body weight for every step walked.
Weakness of muscles around the joint, previous injuries to the joint and heavy manual occupational overuse are also a common risk factors.
Osteoarthritis can arise as a side effect of other problems that put abnormal stress on the joints, such as abnormally shaped hips and knees (added stress is placed on these joints when a person moves), a previous fracture or injury involving the joint.
Other form of arthritis like rheumatoid arthritis or psoriatic arthritis can cause damage to joints. However, these arthritides are relatively uncommon in the general population.
