The immune system is a network of tissues, organs, and cells. Its role is to defend the body from invaders, protecting against infections and disease.
An autoimmune disease results from a mistake made by the immune system. The body's immune system accidentally recognizes healthy cells as foreign invaders and begins to attack them. Research shows that autoimmune diseases tend to have underlying genetic, racial, and gender components.
Autoimmune disorders are difficult to diagnose and often share symptoms. In this article we outline some of the more common autoimmune diseases and how they are treated.
Common autoimmune diseases
The NIH estimate that around 24 million Americans have an autoimmune disease.
According to the National Institutes of Health (NIH), around 24 million Americans have at least one autoimmune disease.
The NIH only include 24 diseases in this statistic, so this number may be a conservative estimate.
Below are some of the most common autoimmune diseases:
Also known as gluten intolerance. Celiac disease is an autoimmune disease where the lining of the small intestine becomes inflamed after eating foods that contain the protein gluten; gluten is found in wheat, rye, and barley, among other foods.
Rheumatoid arthritis (RA)
RA is one of the most common long-term autoimmune disorders. It causes the immune system to attack tissue, often affecting joints in the hands and feet. Symptoms include painful swelling and stiffness of the joints, particularly in the hands and feet.
Inflammatory bowel disease (IBD)
IBD is a long-term inflammation of the gut and lining of the gastrointestinal tract. Symptoms include stomach cramps, bloating, bloody diarrhea, nausea, and constipation.
There are two main types of IBD - Crohn's disease, a chronic inflammation that affects anywhere from the mouth to end of the large intestine, and ulcerative colitis, a long-term inflammation of the large intestine.
A condition that occurs when the adrenal glands fail to produce enough cortisol and aldosterone hormones. Addison's disease leads to low blood pressure, tiredness, dizziness upon standing, low blood sugar, tiredness, dehydration, loss of appetite, nausea, and skin darkening.
Type 1 diabetes
Type 1 diabetes is also referred to as insulin-dependent diabetes mellitus. This autoimmune disease occurs when the pancreas makes insufficient or no insulin, resulting in uncontrolled blood sugar. Symptoms include frequent urination, increased thirst, loss of energy, blurred vision, hunger, and nausea.
A condition marked by loss of skin pigment or the loss of large patches of skin color. The discoloration is often more marked in individuals with darker skin.
A condition that causes inflammation of the thyroid gland; over time it results in underproduction of thyroid hormone. Symptoms include weight gain, tiredness, depression, joint stiffness, and increased sensitivity to cold.
Systemic Lupus Erythematosis (SLE, lupus)
SLE is a range of conditions marked by inflammation of the skin, joints, and, when severe, the internal organs. Symptoms include muscle and joint pain, rash, tiredness, and fever.
Autoimmune diseases can affect practically anyone, but there are certain factors that increase risk. These include:
- Genetics: Research suggests that a family history of autoimmune disease is a strong risk factor.
- Gender: Women are at a greater risk of autoimmune disease than men. Researchers are unsure why, but hormonal factors or the fact that women tend to have stronger immune systems may play a role.
- Age: Autoimmune disorders often occur in young adults and those in middle age.
- Ethnicity: Native American, Latino, and African-Americans generally develop autoimmune disorders at a much higher rate than Caucasians.
- Infection: If a genetically predisposed individual has suffered from specific viral or bacterial infections, there is a greater risk that they will also get an autoimmune disease in the future. While the reason behind this risk remains unclear, research continues to examine the role of previous infections on at-risk immune systems.
Since many autoimmune diseases share similar symptoms, diagnosis is often challenging.
For example, lupus affects the joints in a similar way to RA but tends to be less severe. Lyme disease also causes joint stiffness and inflammation similarly to RA but is caused by a tick carrying the human infecting bacterium known as B. burgdorferi.
IBD has similar symptoms to celiac disease, but IBD is not typically caused by eating foods containing gluten.
Cutaneous T cell lymphoma (CTCL) is a type of immune system cancer. It is caused by a mutation of T cells and presents symptoms such as skin rashes and itchiness. CTCL is sometimes missed during its early stages because its symptoms are so similar to eczema or psoriasis.
Blood tests measure the amount of white and red blood cells. These cells signal whether or not the immune system is fighting something.
The diagnosis of autoimmune diseases differs based on the specific disease. Rheumatoid arthritis, for example, may be diagnosed after a physical exam, blood test, or X-ray. These tests can determine the type of arthritis as well as how severe it is.
Diseases can sometimes take years to diagnose because many symptoms of autoimmune disorders mimic other diseases. Conditions like lupus and celiac disease may be misdiagnosed in their early stages because their symptoms are so similar to other conditions.
Hashimoto's disease and Graves' disease are a bit simpler to diagnose as they usually rely on simple thyroid tests to determine levels of thyroid hormone and other tests specific to the thyroid gland.
An autoimmune disease usually centers around the immune system and the antibodies produced by this system. As a result, diagnosis often involves testing for specific autoantibodies.
A complete blood count may be ordered to measure the amount of white and red blood cells. When the immune system is fighting something, the number of white and red blood cells will differ from normal levels.
Other tests can determine if there is any unusual inflammation in the body. Inflammation is a symptom that is fairly common among all autoimmune diseases. These tests include a C-reactive protein test and an erythrocyte sedimentation rate test.
A doctor should be seen right away as soon as symptoms begin. While symptoms may not always be caused by an autoimmune disease, it's best to tackle any issues right away than wait for them to get worse.
Treatment also varies depending on the type of disorder. For example, type 1 diabetes relies on insulin therapy. Addison's disease requires steroid hormone replacement therapy (HRT). Celiac disease is improved and maintained with a gluten-free diet. RA is often managed with physical therapy and immunosuppressive anti-inflammatory medications.