What Is Arthritis?

Many people start to feel pain and stiffness in their bodies over time. Sometimes their hands or knees or shoulders get sore and are hard to move and may become swollen. These people may have arthritis (ar-THRY-tis). Arthritis may be caused by inflammation (in-fl ah-MAY-shun), of the tissue lining the joints. Some signs of inflammation include redness, heat, pain, and swelling. These problems are telling you that something is wrong.

Joints are places where two bones meet, such as your elbow or knee. Over time, in some types of arthritis but not in all, the joints involved can become severely damaged.

There are different types of arthritis. In some diseases in which arthritis occurs, other organs, such as your eyes, your chest, or your skin can also be affected. Some people may worry that arthritis means they won't be able to work or take care of their children and their family. Others think that you just have to accept things like arthritis.

Common Kinds of Arthritis

Arthritis is one of the most common diseases in this country. Millions of adults and half of all people age 65 and older are troubled by this disease. Older people most often have osteoarthritis, rheumatoid arthritis, or gout.

Osteoarthritis (OA) is the most common type of arthritis in older people. OA starts when cartilage begins to become ragged and wears away. Cartilage is the tissue that pads bones in a joint. At OA’s worst, all of the cartilage in a joint wears away, leaving bones that rub against each other. You are most likely to have OA in your hands, neck, lower back, or the large weight-bearing joints of your body, such as knees and hips.

OA symptoms can range from stiffness and mild pain that comes and goes with activities like walking, bending, or stooping to severe joint pain that keeps on even when you rest or try to sleep. Sometimes OA causes your joints to feel stiff when you haven’t moved them in a while, like after riding in the car. But the stiffness goes away when you move the joint. In time OA can also cause problems moving joints and sometimes disability if your back, knees, or hips are affected.

What causes OA?

Growing older is what most often puts you at risk for OA. Other than that, scientists think the cause depends on which part of the body is involved. For example, OA in the hands or hips may run in families. OA in the knees can be linked with being overweight. Injuries or overuse may cause OA in joints such as knees, hips, or hands.

Rheumatoid Arthritis (RA) is an autoimmune disease. In RA, that means your body attacks the lining of a joint just as it would if it were trying to protect you from injury or disease. For example, if you had a splinter in your finger, the finger would become inflamed—painful, red, and swollen. RA leads to inflammation in your joints. This inflammation causes pain, swelling, and stiffness that lasts for hours. This can often happen in many different joints at the same time. You might not even be able to move the joint. People with RA often don’t feel well. They may be tired or run a fever. People of any age can develop RA, and it is more common in women.

RA can attack almost any joint in the body, including the joints in the fingers, wrists, shoulders, elbows, hips, knees, ankles, feet, and neck. If you have RA in a joint on one side of the body, the same joint on the other side of your body will probably have RA also. RA not only destroys joints. It can also attack organs such as the heart, muscles, blood vessels, nervous system, and eyes.

Gout is one of the most painful forms of arthritis. An attack can begin when crystals of uric acid form in the connective tissue and/or joint spaces. These deposits lead to swelling, redness, heat, pain, and stiffness in the joint. Gout attacks often follow eating foods like shellfish, liver, dried beans, peas, anchovies, or gravy. Using alcohol, being overweight, and certain medications may also make gout worse. In older people, some blood pressure medicines can also increase your chance of a gout attack.

Gout is most often a problem in the big toe, but it can affect other joints, including your ankle, elbow, knee, wrist, hand, or other toes. Swelling may cause the skin to pull tightly around the joint and make the area red or purple and very tender. Your doctor might suggest blood tests and x-rays. He or she might also take a sample of fluid from your joint while you are having an attack.

Other forms of arthritis include psoriatic arthritis (in people with the skin condition psoriasis), ankylosing spondylitis (which mostly affects the spine), reactive arthritis (arthritis that occurs as a reaction to another illness in the body), and arthritis in the temporomandibular joint (where the jaw joins the skull).