A disease that results when the immune system mistakenly attacks the body’s own tissues. Examples include multiple sclerosis, type 1 diabetes, rheumatoid arthritis, and systemic lupus erythematosus. Autoimmune diseases can affect almost any part of the body, including the heart, brain, nerves, muscles, skin, eyes, joints, lungs, kidneys, glands, the digestive tract, and blood vessels.
The classic sign of an autoimmune disease is inflammation, which can cause redness, heat, pain, and swelling.
How an autoimmune disease affects you depends on what part of the body is targeted. Many autoimmune diseases don’t restrict themselves to one part of the body. For example, SLE can affect the skin, joints, kidneys, heart, nerves, blood vessels, and more.