Osteoarthritis is a "mechanical" disease of the joints. This is a progressive erosion of the cartilage. It is often linked to aging and therefore more common among seniors. It is a disease that affects twice as many women as men and mainly affects the joints of the knee, hip and spine.

In case of osteoarthritis, there is pain in the movements, crunches and deformations of the joints.

Risk factors include: overweight and obesity, metabolic syndrome, heavy physical labor, joint trauma (eg sprains), joint dislocations, family history and arthritis. Arthritis is a chronic autoimmune disease. It is an inflammation of the joints that can be declared at any age. It affects three times more women than men and mainly affects the joints of the hands and feet.

In case of arthritis, there is a morning stiffness, the joints are painful and swollen. The person feels fatigue and the pain increases at rest (especially at night).
 
The main risk factors are family history and environmental factors (eg smoking).

The physical and biological signs, causes and treatments of these two diseases are therefore very different.