Osteoarthritis: Sometimes called degenerative arthritis, osteoarthritis is the most common type of arthritis. It's a wear-and-tear condition that occurs when the cartilage in your knee deteriorates with use and age.
Rheumatoid arthritis: The most debilitating form of arthritis, rheumatoid arthritis is an autoimmune condition that can affect almost any joint in your body, including your knees. Although rheumatoid arthritis is a chronic disease, it tends to vary in severity and may even come and go.
Gout: This type of arthritis occurs when uric acid crystals build up in the joint. While gout most commonly affects the big toe, it can also occur in the knee.
Pseudogout: Often mistaken for gout, pseudogout is caused by calcium-containing crystals that develop in the joint fluid. Knees are the most common joint affected by pseudogout.
Septic arthritis: Sometimes your knee joint can become infected, leading to swelling, pain and redness. Septic arthritis often occurs with a fever, and there's usually no trauma before the onset of pain. Septic arthritis can quickly cause extensive damage to the knee cartilage.
Courtesy: Mayo Clinic
