An autoimmune disease develops when your immune system, which defends your body against disease, treat your healthy cells as foreign. Consequently, your immune system attacks healthy cells. Depending on the type, an autoimmune disease can affect one or many different types of body tissue.

Here and now

  • It is estimated that 1.3 million Americans live with rheumatoid arthritis.

  • Over 1.4 million Americans live with Crohn’s disease or ulcerative colitis.

  • Alopecia areata affects roughly 6.5 million Americans.

  • Worldwide, over 2.3 million people are affected by multiple sclerosis.

The facts

  • There are 80-100 different autoimmune diseases identified by researchers.

  • Autoimmune disease is one of the top 10-leading causes of death in female children and women in all age groups, up to 64 years of age.

  • Close genetic relationships exist among autoimmune diseases.

  • Many autoimmune diseases have the same symptoms, making them very difficult to diagnose. Common symptoms include fatigue, fever and general malaise (feeling ill).

  • Autoimmune diseases affect many parts of the body. The most common organs and tissues affected are joints, muscles, skin, red blood cells, blood vessels, connective tissue and endocrine glands.

The big five

Autoimmune diseases affect 50 million Americans. Often a source of chronic discomfort, cramps and outright pain, they exact a physical, financial and emotional toll on patients. We have yet to pinpoint the cause of these diseases, but we do know that close genetic relationships exist among them.

1. Rheumatoid arthritis

A form of arthritis that causes pain, swelling, stiffness and loss of function in your joints. It can affect any joint, but is common in the wrist and fingers. More women than men get rheumatoid arthritis. It often starts in middle age and is most common in older people. But children and young adults can also get it. Medication costs can reach $20,000 per year.

2. Crohn’s disease

An inflammatory autoimmune bowel disease characterized by severe and persistent inflammation of the lining or wall of the gastrointestinal tract.

3. Ulcerative colitis

An autoimmune related disease that causes inflammation and sores, called ulcers, in the lining of the rectum and colon. It is one of a group of diseases called inflammatory bowel disease. Ulcerative colitis can happen at any age, but it usually starts between the ages of 15 and 30.

4. Multiple sclerosis

A nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of multiple sclerosis. They can include visual disturbances, muscle weakness, trouble with coordination and balance, sensations such as numbness, prickling, or “pins and needles” and thinking and memory problems. No one knows what causes multiple sclerosis.

5. Alopecia areata

An autoimmune disorder characterized by hair loss. It is found equally in both men and women. The disease can occur at any age, including childhood.