Usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint.
It is also due to invasion of a joint by an infectious agent. Septic arthritis is a medical emergency.Rheumatoid arthritis is a chronic, systemic, inflammatory disease, most often involving the small joints of the hands and feet, although any joint can be affected.

Osteoarthritis (OA) also known as degenerative arthritis is a group of mechanical and biological events affecting the elderly population and is caused due to degradation of joints, including articular cartilage and subchondral bone.