What is an autoimmune disease?
What is an autoimmune disease?
An autoimmune disease develops when your immune system, which defends your body against disease, decides your healthy cells are foreign. As a result, your immune system attacks healthy cells.
For instance, when an intruder invades your body—like a cold virus or bacteria on a thorn that pricks your skin—your immune system protects you. It tries to identify, kill and eliminate the invaders that might hurt you. But sometimes problems with your immune system cause it to mistaken your body’s own healthy cells as invaders and then repeatedly attacks them. This is called an autoimmune disease.
According to the American Autoimmune Related Diseases Association (AARDA), Autoimmune disease affects up to 50 million Americans.
Depending on the type, an autoimmune disease can affect one or many different types of body tissue. It can also cause abnormal organ growth and changes in organ function.
Autoimmune diseases usually fluctuate between periods of remission (little or no symptoms) and flare-ups (worsening symptoms). Currently, treatment for autoimmune diseases focuses on relieving symptoms because there is no curative therapy.
There are as many as 80 types of autoimmune diseases. Many of them have similar symptoms, which makes them very difficult to diagnose. It’s also possible to have more than one at the same time.
The cause of autoimmune disease is unknown. There are many theories about what triggers autoimmune diseases, including:
- bacteria or virus
- drugs
- chemical irritants
- environmental irritants
- stress
How are autoimmune diseases diagnosed?
Ordinarily, your immune system produces antibodies (proteins that recognize and destroy specific substances) against harmful invaders in your body. These invaders include:
- viruses
- bacteria
- parasites
- fungi
When you have an autoimmune disease, your body produces antibodies against some of your own tissues. Diagnosing an autoimmune disease involves identifying the antibodies your body is producing.
The following tests are used to diagnose an autoimmune disease:
- autoantibody tests: any of several tests that look for specific antibodies to your own tissues
- antinuclear antibody tests: a type of autoantibody test that looks for antinuclear antibodies, which attack the nuclei of cells in your body
- complete blood count: measures the numbers of red and white cells in your blood; when your immune system is actively fighting something, these numbers will vary from the normal
- C-reactive protein (CRP): elevated CRP is an indication of inflammation throughout your body
- erythrocyte sedimentation rate: this test indirectly measures how much inflammation is in your body
The following are some of the more common autoimmune diseases:
rheumatoid arthritis: inflammation of joints and surrounding tissues
systemic lupus erythematosus: affects skin, joints, kidneys, brain, and other organs
celiac sprue disease: a reaction to gluten (found in wheat, rye, and barley) that causes damage to the lining of the small intestine
pernicious anemia: decrease in red blood cells caused by inability to absorb vitamin B-12
vitiligo: white patches on the skin caused by loss of pigment
scleroderma: a connective tissue disease that causes changes in skin, blood vessels, muscles, and internal organs
psoriasis: a skin condition that causes redness and irritation as well as thick, flaky, silver-white patches
inflammatory bowel diseases: a group of inflammatory diseases of the colon and small intestine
Hashimoto’s disease: inflammation of the thyroid gland
Addison’s disease: adrenal hormone insufficiency
Graves’ disease: overactive thyroid gland
reactive arthritis: inflammation of joints, urethra, and eyes; may cause sores on the skin and mucus membranes
Sjögren’s syndrome: destroys the glands that produce tears and saliva causing dry eyes and mouth; may affect kidneys and lungs
type 1 diabetes: destruction of insulin producing cells in the pancreas