There are several common types of arthritis.

Osteoarthritis

This is the most common type of arthritis. The ends of bones in joints have a slippery, cushioning substance called cartilage. Cartilage acts as a shock absorber and allows bones to slide smoothly against each other.

Cartilage can weaken with age, injuries, or infections leaving bones unprotected. Bones then start to grind against each other with movement, causing pain.

Small holes and breaks can start in the bone surface. Then, bony growths—called osteophytes or bone spurs—may begin to appear. Sometimes, small bone fragments or bits of cartilage break off and interfere with the movement of the joint, causing more swelling and pain.

Bones, ligaments, blood vessels, nerves, and muscles can become irritated and inflamed.

Rheumatoid Arthritis

This is the second most common form of arthritis. Rheumatoid arthritis affects many joints in the hands, wrists, elbows, shoulders, and feet. This disease is often a life-long disease that can get worse with time.

In this type of arthritis, a person’s immune system starts attacking the tissues in their joints. One of the tissues is the synovium. This is a thin lining over bones that helps keep joints moving.

Rheumatoid arthritis also can attack muscles, blood vessels, heart, lungs, nerves, and skin.

Many people get rheumatoid arthritis before age 60. Others get it as older adults. The older group is more likely to have:

• Much early morning stiffness
• Pain in the shoulders, wrists, and hands

Gout

Gout is caused by the build-up of uric acid crystals within a joint. Uric acid is a waste product found in the blood. The body makes uric acid when it breaks down chemicals found in certain foods and drinks. Usually the kidneys filter out uric acid into the urine. Sometimes the body makes too much uric acid, or the kidneys are not able to remove it fast enough. High levels of uric acid can settle in the joints, creating crystals which clump together. This build-up causes intense pain, swelling, warmth, and redness.

Infectious Arthritis

This type of arthritis occurs when an infection spreads into a joint, causing pain, swelling, warmth, and redness.

Last Updated April 2023