Why do arthritis attack people?

Answer 1

Rheumatoid arthritis is a chronic joint disease that damages the joints of the body. It is also a systemic disease that potentially affects internal organs of the body and leads to disability. The joint damage is caused by inflammation of the joint lining tissue. Inflammation is normally a response by the body's immune system to "assaults" such as infections, wounds, and foreign objects. In rheumatoid Arthritis, the inflammation is misdirected to attack the joints. Rheumatoid arthritis is often referred to as RA.

• The inflammation in the joints causes pain, stiffness, swelling, and loss of function.
• The inflammation often affects other organs and systems of the body, including the lungs, heart, and kidneys.
• If the inflammation is not slowed or stopped, it can permanently damage the affected joints and other tissues.

Rheumatoid arthritis should not be confused with other forms of arthritis, such as osteoarthritis or arthritis associated with infections. Rheumatoid arthritis is an autoimmune disease. This means that the body's immune system mistakenly attacks the tissues it is supposed to protect.

• The immune system produces specialized cells and chemicals, which are released into the bloodstream and begin to attack body tissues.
• This abnormal immune response causes inflammation and thickening of the membrane (synovium) that lines the joint. Inflammation of the synovium is called synovitis and is the hallmark of an inflammatory arthritis such as rheumatoid arthritis.
• As the synovitis expands inside and outside of the joint, it can damage the bone and cartilage of the joint and the surrounding tissues, such as ligaments, tendons, nerves, and blood vessels.

Rheumatoid arthritis most often affects the smaller joints, such as those of the hands and/or feet, wrists, elbows, knees, and/or ankles, but any joint can be affected. The symptoms often lead to significant discomfort and disability.

• Many people with rheumatoid arthritis have difficulty carrying out normal activities of daily living, such as standing, walking, dressing, washing, using the toilet, preparing food, and carrying out household chores.
• The symptoms of rheumatoid arthritis interfere with work for many people. As many as half of those with rheumatoid arthritis are no longer able to work 10-20 years after their condition is diagnosed.
• On average, life expectancy is somewhat shorter for people with rheumatoid arthritis than for the general population. This does not mean that everyone with rheumatoid arthritis has a shortened life span. Rheumatoid arthritis itself is not a fatal disease. However, it can be associated with many complications and treatment-related side effects that can contribute to premature death.

Although rheumatoid arthritis most often affects the joints, it is a disease of the entire body. It can affect many organs and body systems besides the joints. Therefore, rheumatoid arthritis is referred to as a systemic disease.

• Musculoskeletal structures: Damage to muscles surrounding joints may cause atrophy (shrinking) that results in weakening. This is most common in the hands. Atrophy also may result from not using a muscle, usually because of pain or swelling. Damage to bones and tendons can cause deformities, especially of the hands and feet. Osteoporosis and carpal tunnel syndrome are other common complications of rheumatoid arthritis.
• Skin: Many people with rheumatoid arthritis develop small nodules on or near the joint that are visible under the skin. These rheumatoid nodules are most noticeable under the skin on the bony areas that stick out when a joint is flexed. Dark purplish areas on the skin (purpura) are caused by bleeding into the skin from blood vessels damaged by rheumatoid arthritis. Purpura is particularly common in those patients who have taken cortisone medication. This damage to the blood vessels is called vasculitis, and these vasculitic lesions also may cause skin ulcers.
• Heart: A collection of fluid around the heart (pericardial effusion) from inflammation is not uncommon in rheumatoid arthritis. This usually causes only mild symptoms, if any, but it can be very severe. Rheumatoid arthritis-related inflammation can affect the heart muscle, the heart valves, or the blood vessels of the heart (coronary arteries). Heart attacks are more frequent in patients with rheumatoid arthritis than those without it.
• Lungs: Rheumatoid arthritis' effects on the lungs may take several forms. Fluid may collect around one or both lungs and is referred to as a pleural effusion. Inflammation of the lining tissues of the lungs is known as pleuritis. Less frequently, lung tissues may become stiff or scarred, referred to as pulmonary fibrosis. Any of these effects can have a negative effect on breathing. Lung infections become more common.
• Digestive tract: The digestive tract is usually not affected directly by rheumatoid arthritis. Dry mouth, related to Sjögren's syndrome, is the most common symptom of gastrointestinal involvement. Digestive complications are much more likely to be caused by medications used to treat the condition, such as gastritis (stomach inflammation) or stomach ulcer caused by NSAID therapy. Any part of the digestive tract may become inflamed if the patient develops vasculitis, but this is uncommon. If the liver is involved, it may become enlarged and cause discomfort in the abdomen.
• Kidneys: The kidneys are not usually affected directly by rheumatoid arthritis. Kidney problems in rheumatoid arthritis are much more likely to be caused by medications used to treat the condition. Nevertheless, severe, long-standing disease can uncommonly lead to a form of protein deposition and damage to the kidney, referred to as amyloidosis.
• Blood vessels: Inflammation of the blood vessels can cause problems in any organ but is most common in the skin, where it appears as purple patches (purpura) or skin ulcers.
• Blood: Anemia or "low blood" is a common complication of rheumatoid arthritis. Anemia means that you have an abnormally low number of red blood cells and that these cells are low in hemoglobin, the substance that carries oxygen through the body. (Anemia has many different causes and is by no means unique to rheumatoid arthritis.) A low white blood cell count (leukopenia) can occur from Felty's syndrome, a complication of rheumatoid arthritis that is also characterized by enlargement of the spleen.
• Nervous system: The deformity and damage to joints in rheumatoid arthritis often lead to entrapment of nerves. Carpal tunnel syndrome is one example of this. Entrapment can damage nerves and may lead to serious consequences.
• Eyes: The eyes commonly become dry and/or inflamed in rheumatoid arthritis. This is a result of inflammation of the tear glands and is called Sjögren's syndrome. The severity of this condition depends on which parts of the eye are affected. There are many other eye complications of rheumatoid arthritis, including inflammation of the whites of the eyes (scleritis), that often require the attention of an ophthalmologist.

Like many autoimmune diseases, rheumatoid arthritis typically waxes and wanes. Most people with rheumatoid arthritis experience periods when their symptoms worsen (known as flares or active disease) separated by periods in which the symptoms improve. With successful treatment, symptoms may even go away completely (remission, or inactive disease).

About 1.3 million people in the United States are believed to have rheumatoid arthritis.

• About 75% of these are women. Women are two to three times more likely to develop rheumatoid arthritis than men.
• Rheumatoid arthritis affects all ages, races, and social and ethnic groups.
• It is most likely to strike people 35-50 years of age, but it can occur in children, teenagers, and elderly people. (A similar disease affecting young people is known as juvenile rheumatoid arthritis.)
• Worldwide, about 1% of people are believed to have rheumatoid arthritis, but the rate varies among different groups of people. For example, rheumatoid arthritis affects about 5%-6% of some Native-American groups, while the rate is very low in some Caribbean peoples of African descent.
• The rate is about 2%-3% in people who have a close relative with rheumatoid arthritis, such as a parent, brother or sister, or child.

Although there is no cure for rheumatoid arthritis, the disease can be controlled in most people. Early, aggressive therapy, soon after the initial diagnosis, is optimally targeted to stop or slow down inflammation in the joints can prevent or reduce symptoms, prevent or reduce joint destruction and deformity, and prevent or lessen disability and other complications.