Specifically, rheumatoid arthritis is a type of chronic arthritis that normally occurs in joints on both sides of the body, such as hands, wrists, or knees. The symmetry of this condition helps to distinguish it from other types of arthritis. In addition to affecting the joints, rheumatoid arthritis may also affect the skin, eyes, lungs, heart, blood, or nerves.

The most common symptoms of rheumatoid arthritis include joint pain and swelling, stiffness, especially in the morning or after sitting for long periods, and fatigue. Affecting about 1 percent of the U.S. population, most people experience joint symptoms which develop gradually over several years. However, for some rheumatoid arthritis can progress rapidly, or it may strike for a limited period of time and then enter a period of remission. Rheumatoid arthritis is two to three times more common in women than in men, but men tend to be more severely affected by the disease.

The exact cause of rheumatoid arthritis is unknown. However, it is believed to be due to a combination of genetic, environmental, and hormonal factors. In patients with rheumatoid arthritis, the immune system is triggered to attack the joints and sometimes the organs. Theories have suggested that a virus or bacteria may alter the immune system, causing it to attack the joints. While research has not been able to determine exactly what role genetics play, some patients do seem to have a genetic or inherited factor that increases their chances of developing rheumatoid arthritis.

Once the immune system is triggered, a patient with rheumatoid arthritis begins to produce inflammatory substances within his or her joints. An increase in the number of cells and the inflammatory substances within the joints cause irritation, a wearing down of the cartilage, and swelling and inflammation in the joint lining. Inflammation within the joint lining causes it to produce excessive joint fluid within the joint.

With the wearing down of cartilage, bones can begin to rub against one another. As the joint lining expands, it can invade or erode into adjacent bone causing bone damage. This also causes the joints to become painful and warm to the touch.

Physicians diagnose rheumatoid arthritis based on a number of factors including:
1.The specific location and symmetry of painful joints, especially in the hands.
2.The presence of joint stiffness in the morning.
3.The presence of bumps and nodules under the skin
4.Results of x-ray tests that suggest rheumatoid arthritis.
5.Positive results of a blood test called the rheumatoid factor.

Recent major studies have indicated the dramatic benefits of early treatment with rheumatoid arthritis medication. Early intensive treatment with a combination of medications offers a chance of remission. In comparison to 20 years ago, studies show that those who have been diagnosed with rheumatoid arthritis today are receiving more aggressive treatment, and require fewer joint replacement surgeries than their predecessors.

"When you begin these treatments early on," said Eric Matteson, rheumatologist MD, Mayo Clinic, "you are less likely to develop erosive disease in the joints, and less likely to develop other related conditions such as lung disease, vasculitis, and pericarditis, all of which are major contributors to early mortality in people with rheumatoid arthritis."

However, plenty of data also suggests that even a late diagnosis and treatment of rheumatoid arthritis can be effective. It's never too early, and never too late," said Theodore Fields, MD, FACP, clinical director of the Gosden-Robinson Early Arthritis Center at New York's Hospital for Special Surgery. "There's plenty of data that even treating late does help."