Autoimmune Diseases

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A healthy immune system defends the body against disease and infection. But if the immune system malfunctions, it mistakenly attacks healthy cells, tissues, and organs. Called autoimmune disease, these attacks can affect any part of the body, weakening bodily function and even turning life-threatening.

Scientists know about more than 80 autoimmune diseases. Some are well known, such as type 1 diabetes, multiple sclerosis, lupus, and rheumatoid arthritis, while others are rare and difficult to diagnose. With unusual autoimmune diseases, patients may suffer years before getting a proper diagnosis. Most of these diseases have no cure. Some require lifelong treatment to ease symptoms.

infographic with anatomy images describing symptoms


Autoimmune diseases are affecting more people. As many as 50 million people in the U.S. have an autoimmune disease, making it the third most prevalent disease category, surpassed only by cancer and heart disease. A person’s genes in combination with infections and other environmental exposures likely play a significant role in disease development. 

Nearly 80% of people with a chronic autoimmune condition are women. These autoimmune diseases include rheumatoid arthritis, multiple sclerosis, scleroderma, lupus, Sjögren’s syndrome, and others. Researchers are conducting studies to understand why there is a sex-biased trend in this disease category.

Studies indicate these diseases likely result from interactions between genetic and environmental factors. Gender, race, and ethnicity characteristics are linked to a likelihood of developing an autoimmune disease.1  Autoimmune diseases are more common when people are in contact with certain environmental exposures, as described below.

  1. <span></span><span>Ramos PS, Shedlock AM, Langefeld, CD. 2015. Genetics of autoimmune diseases: insights from population genetics. <em>J Hum Genet</em>. 60(11): 657–664. [<a href="" target="_blank">Abstract <span class="screenreader">Ramos PS, Shedlock AM, Langefeld, CD. 2015. Genetics of autoimmune diseases: insights from population genetics. J Hum Genet. 60(11): 657–664.</span></a>]</span>

What is NIEHS Doing?

Unraveling the genetic and environmental underpinnings of autoimmune disease is a focus at NIEHS and the National Toxicology Program (NTP). Progress happens through multiple research efforts, such as:

  • Sunlight associated with autoimmune disease – This NIEHS study suggests exposure to ultraviolet radiation from sunlight may be connected to the development of juvenile dermatomyositis, an autoimmune disease associated with muscle weakness and skin rashes.
  • Childhood poverty linked to rheumatoid arthritis in adulthood – NIEHS researchers discovered a link between lower socioeconomic status in childhood and rheumatoid arthritis in adulthood. The effect of lower childhood socioeconomic status and lower adult education level equaled the combined effect of having both a paternal and personal history of smoking.
  • Agricultural chemicals and rheumatoid arthritis – Researchers at NIEHS found that exposure to some pesticides may play a role in the development of rheumatoid arthritis in male farm workers.
  • Organic mercury may trigger autoimmune disease – In a study funded by NIEHS, methylmercury, even at exposure levels generally considered safe, may be linked to development of autoimmune antibodies in women of reproductive age. These antibodies could lead in turn to autoimmune diseases, such as inflammatory bowel disease, lupus, rheumatoid arthritis, and multiple sclerosis.
  • Genetic factors in autoimmune muscle disease – NIEHS researchers identified the primary genetic risk factors associated with autoimmune muscle disease in Caucasian populations in Europe and the United States.
  • Gene-environment interaction in rheumatoid arthritis – A study funded by NIEHS pinpointed the mechanics of a gene-environment interaction that could explain why the genetic risk for rheumatoid arthritis is amplified by environmental pollutants like cigarette smoke.
  • Role of nutrition in development of autoimmune disease – NIEHS-funded research indicates that vitamin D may be important for preventing immune dysfunction in older populations. Another study funded by NIEHS found that dietary micronutrients could either improve or worsen lupus symptoms.

Further Reading

Stories from the Environmental Factor (NIEHS Newsletter)

Fact Sheets

Autoimmune Diseases and Your Environment

Additional Resources

Related Health Topics

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