Skip to content
My WebMD Sign In, Sign Up
Select An Article
Font Size

What Is Rheumatoid Arthritis?

Arthritis means inflammation in a joint. Joint inflammation causes redness, warmth, swelling, and pain within the joint.

Rheumatoid arthritis is a type of chronic arthritis that occurs in joints on both sides of the body (such as both hands, both wrists, or both knees). This symmetry helps distinguish rheumatoid arthritis from other types of arthritis.

Recommended Related to Rheumatoid Arthritis

Getting a Grip on Rheumatoid Arthritis Pain

When you work on the Verrazano-Narrows, one of the biggest suspension bridges in the world, the cold temperatures and heavy lifting can really take a toll on your body. Construction worker John Melendez thought the pain and swelling he was experiencing in his hands, arms, and legs were just side effects of his job. Eventually, the pain became so severe that the 52-year-old Staten Island resident was unable to work at all. “My fingers were so swollen that I couldn’t bend them,” Melendez recalls. “I...

Read the Getting a Grip on Rheumatoid Arthritis Pain article > >

Rheumatoid arthritis may also affect the skin, eyes, lungs, heart, blood, or nerves.

What Are the Symptoms of Rheumatoid Arthritis?

Symptoms of rheumatoid arthritis are:

  • Joint pain and swelling
  • Stiffness, especially in the morning or after sitting for long periods
  • Fatigue

Rheumatoid arthritis affects everyone differently. For some, joint symptoms develop gradually over several years. In others, rheumatoid arthritis may develop quickly, while other people may have rheumatoid arthritis for a short time and then have a time with no symptoms, called remission.

Who Gets Rheumatoid Arthritis?

About 1% of Americans have rheumatoid arthritis. It is an autoimmune disease, meaning the body's immune system attacks its own healthy tissues. Rheumatoid arthritis is two to three times more common in women than in men, but men tend to have more severe symptoms. It usually happens in middle age, but young children and the elderly also can get rheumatoid arthritis.

What Causes Rheumatoid Arthritis?

The cause of rheumatoid arthritis is unknown. It is thought to be due to a combination of genetic, environmental, and hormonal factors. With rheumatoid arthritis, something seems to trigger the immune system to attack the joints and sometimes other organs. Some theories suggest that a virus or bacteria may alter the immune system, causing it to attack the joints. Other theories suggest that smoking may lead to rheumatoid arthritis.

Research hasn't found exactly what role genetics plays in rheumatoid arthritis. Some people do seem to have a genetic or inherited factor that increases their chance of developing rheumatoid arthritis.

How Does Rheumatoid Arthritis Affect the Body?

Once the immune system is triggered, immune cells migrate from the blood into the joints and joint-lining tissue, called synovium. There the immune cells make inflammatory substances that cause irritation, wearing down of cartilage (the cushioning material at the end of bones), and swelling and inflammation of the joint lining. As the cartilage wears down, the space between the bones narrows. As it gets worse, the bones could rub against each other.

Inflammation of the joint lining causes fluid to build up with the joint. As the lining expands, it may damage the bone.

All of these things cause the joint to become very painful, swollen, and warm to the touch.

How Is Rheumatoid Arthritis Diagnosed?

Rheumatoid arthritis is diagnosed from a combination of things, including:

  • The location and symmetry of painful joints, especially the hand joints
  • Joint stiffness in the morning
  • Bumps and nodules under the skin (rheumatoid nodules)
  • Results of X-ray tests
  • Blood tests

WebMD Medical Reference

Next Article:

Today on WebMD

fish oil capsule
Article
senior woman holding green apple
Article
 
young women in yoga class
Video
Man with knee brace
Article
 
Lucille Ball
Slideshow
Hand bones X-ray
Article
 
prescription pills
Article
Woman massaging her neck
Quiz
 
woman roasting vegetables in oven
Slideshow
Woman rubbing shoulder
Slideshow
 
Working out with light weights
Video
arthritis
Article