Rheumatoid Arthritis | Health Topics | NIAMS

Rheumatoid Arthritis
Overview of Rheumatoid Arthritis
Rheumatoid arthritis (RA) is a chronic (long-lasting) autoimmune disease that mostly affects joints. RA occurs when the immune system, which normally helps protect the body from infection and disease, attacks its own tissues. The disease causes pain, swelling, stiffness, and loss of function in joints.
Additional features of rheumatoid arthritis can include the following:
It affects the lining of the joints, which damages the tissue that covers the ends of the bones in a joint.
RA often occurs in a symmetrical pattern, meaning that if one knee or hand has the condition, the other hand or knee is often also affected.
It can affect the joints in the wrists, hands, elbows, shoulders, feet, spine, knees, and jaw.
RA may cause fatigue, occasional fevers, and a loss of appetite.
RA may cause medical problems outside of the joints, in areas such as the heart, lungs, blood, nerves, eyes, and skin.
Fortunately, current treatments can help people with the disease to lead productive lives.
What happens in rheumatoid arthritis?
Doctors do not know why the immune system attacks joint tissues. However, they do know that when a series of events occurs, rheumatoid arthritis can develop. This series of events includes:
A combination of genes and exposure to environmental factors starts the development of RA.
The immune system may be activated years before symptoms appear.
The start of the autoimmune process may happen in other areas of the body, but the impact of the immune malfunction typically settles in the joints.
Immune cells cause inflammation in the inner lining of the joint, called the synovium.
This inflammation becomes chronic, and the synovium thickens due to an increase of cells, production of proteins, and other factors in the joint, which can lead to pain, redness, and warmth.
As RA progresses, the thickened and inflamed synovium pushes further into the joint and destroys the cartilage and bone within the joint.
As the joint capsule stretches, the forces cause changes within the joint structure.
The surrounding muscles, ligaments, and tendons that support and stabilize the joint become weak over time and do not work as well. This can lead to more pain and joint damage, and problems using the affected joint.
Who Gets Rheumatoid Arthritis?
You are more likely to get rheumatoid arthritis if you have certain risk factors. These include:
Age. The disease can happen at any age; however, the risk for developing rheumatoid arthritis increases with older age. Children and younger teenagers may be diagnosed with juvenile idiopathic arthritis, a condition related to rheumatoid arthritis.
Sex. Rheumatoid arthritis is more common among women than men. About two to three times as many women as men have the disease. Researchers think that reproductive and hormonal factors may play a role in the development of the disease for some women.
Family history and genetics. If a family member has RA, you may be more likely to develop the disease. There are several genetic factors that slightly increase the risk of getting RA.
Smoking. Research shows that people who smoke over a long period of time are at an increased risk of getting rheumatoid arthritis. For people who continue to smoke, the disease may be more severe.
Obesity. Some research shows that being obese may increase your risk for the disease as well as limit how much the disease can be improved.
Periodontitis. Gum disease may be associated with developing RA.
Lung diseases. Diseases of the lungs and airways may also be associated with developing RA.
Symptoms of Rheumatoid Arthritis
Common symptoms of rheumatoid arthritis include:
RA affects people differently. In some people, RA starts with mild or moderate inflammation affecting just a few joints. However, if it is not treated or the treatments are not working, RA can worsen and affect more joints. This can lead to more damage and disability.
At times, RA symptoms worsen in “flares” due to a trigger such as stress, environmental factors (such as cigarette smoke or viral infections), too much activity, or suddenly stopping medications. In some cases, there may be no clear cause.
The goal of treatment is to control the disease so it is in remission or near remission, with no signs or symptoms of the disease.
Rheumatoid arthritis can cause other medical problems, such as:
Joint pain at rest and when moving, along with tenderness, swelling, and warmth of the joint.
Joint stiffness that lasts longer than 30 minutes, typically after waking in the morning or after resting for a long period of time.
Joint swelling that may interfere with daily activities, such as difficulty making a fist, combing hair, buttoning clothes, or bending knees.
Fatigue – feeling unusually tired or having low energy.
Occasional low-grade fever.
Loss of appetite.
Rheumatoid arthritis can happen in any joint; however, it is more common in the wrists, hands, and feet. The symptoms often happen on both sides of the body, in a symmetrical pattern. For example, if you have RA in the right hand, you may also have it in the left hand.
RA affects people differently. In some people, RA starts with mild or moderate inflammation affecting just a few joints. However, if it is not treated or the treatments are not working, RA can worsen and affect more joints. This can lead to more damage and disability.
At times, RA symptoms worsen in “flares” due to a trigger such as stress, environmental factors (such as cigarette smoke or viral infections), too much activity, or suddenly stopping medications. In some cases, there may be no clear cause.
The goal of treatment is to control the disease so it is in remission or near remission, with no signs or symptoms of the disease.
Rheumatoid arthritis can cause other medical problems, such as:
Rheumatoid nodules that are firm lumps just below the skin, typically on the hands and elbows.
Anemia due to low red blood cell counts.
Neck pain.
Dry eyes and mouth.
Inflammation of the blood vessels, the lung tissue, airways, the lining of the lungs, or the sac enclosing the heart.
Lung disease, characterized by scarring and inflammation of the lungs that can be severe in some people with RA.
Causes of Rheumatoid Arthritis
Researchers do not know what causes the immune system to turn against the body’s joints and other tissues. Studies show that a combination of the following factors may lead to the disease:
Genes. Certain genes that affect how the immune system works may lead to rheumatoid arthritis. However, some people who have these genes never develop the disease. This suggests that genes are not the only factor in the development of RA. In addition, more than one gene may determine who gets the disease and how severe it will become.
Environment. Researchers continue to study how environmental factors such as cigarette smoke may trigger rheumatoid arthritis in people who have specific genes that also increase their risk. In addition, some factors such as inhalants, bacteria, viruses, gum disease, and lung disease may play a role in the development of RA.
Sex hormones. Researchers think that sex hormones may play a role in the development of rheumatoid arthritis when genetic and environmental factors also are involved. Studies show: