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Autoimmune Diseases


The Manual's Editorial Staff

Last full review/revision Jan 2021| Content last modified Jan 2021
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What is an autoimmune disease?

"Auto" is a medical term for "self." The immune system is your body's defense system. It helps protect you from illness and infection. The immune system usually attacks invading bacteria, viruses, and cancer cells. With an autoimmune disease, your immune system attacks your own body.

  • There are many different autoimmune diseases

  • Symptoms of autoimmune diseases are different depending on which disease you have and what part of your body is affected

  • Doctors do blood tests to check for an autoimmune disease

  • Doctors treat autoimmune diseases with medicines that slow down the immune system

Autoimmune diseases may attack almost any part of your body:

What causes an autoimmune disease?

Your immune system attacks your healthy tissues. Here’s how it works:

  • Usually, your immune system protects your body from illness by attacking substances (such as bacteria or viruses) that are dangerous or unhealthy

  • In autoimmune diseases, your immune system mistakes healthy parts of your body for an attacking substance

  • Your immune system then attacks your healthy cells or tissues just like they were something that would make you sick

  • This causes the symptoms of an autoimmune disease

Some people are more likely to have an autoimmune disease because it runs in their family.

Women are more likely than men to have an autoimmune disease.

What are the symptoms of an autoimmune disease?

Symptoms are different depending on which disease you have and what part of your body is affected. However, in general, autoimmune diseases cause swelling and tissue damage. You may have one or more of these symptoms:

  • Painful joints

  • Swollen, red joints

  • Itching

Other autoimmune diseases may cause difficulty breathing, jaundice (yellow skin and eyes), weakness, and confusion. You may develop kidney failure.

Sometimes an autoimmune disease may cause death.

How can doctors tell if I have an autoimmune disease?

If doctors suspect an autoimmune disease, they’ll ask about your symptoms, examine you, and do blood tests.

How do doctors treat an autoimmune disease?

Doctors usually:

  • Give you medicines that slow down your immune system and its attack on your body

The most common medicines doctors use are corticosteroids, such as prednisone. Sometimes doctors use stronger drugs to slow down your immune system.

The downside of these medicines is they also make it harder for your body to fight off infection. Some of the medicines also can increase your risk of cancer. Your doctor will watch you closely to help protect you from getting another sickness.

Most autoimmune diseases are long term, and people who have them often need to take medicine for the rest of their lives.

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