Medical Library: Knee – Arthritis
Arthritis literally means “joint inflammation”, and refers to a group of more than 100 rheumatic diseases and other conditions that can cause pain, stiffness and swelling in the joints.
The two most common types of arthritis are osteoarthritis and rheumatoid arthritis. Arthritis can affect anyone at any age, including children. The incidence of arthritis increases with age, but nearly 3 out of 5 people with arthritis are under age 65.
If left undiagnosed and untreated, many types of arthritis can cause irreversible damage to the joints, bones, organs, and skin.
Osteoarthritis, also known as degenerative joint disease, results from wear and tear of the cartilage. The first signs of osteoarthritis are:
- Joint pain
- Joint tenderness
- Joint swelling
- Decreased joint function
Initially, osteoarthritis is non-inflammatory and its onset is subtle and gradual, usually involving one or only a few joints.
The joints most often affected are the:
Risks of osteoarthritis increase with age. Other risk factors include joint injury, obesity, and repetitive use of the joint.