An autoimmune disease is the result of the immune system accidentally attacking your body instead of protecting it. It occurs when your immune system is overactive, causing it to attack and damage your body's own tissue. 

Normally, your immune system creates proteins called antibodies that work to protect you against harmful substances such as viruses, cancer cells and toxins. But with autoimmune disorders, your immune system can't tell the difference between invaders and healthy cells.

CAUSES OF AUTOIMMUNE DISEASES

The exact causes of autoimmune diseases are unknown, scientists have some theories on what triggers them :

• Medications - some drugs may cause changes in your body that confuse your immune system. 
• Genetics - some autoimmune diseases run in families, so there is a higher risk if your family has a history of them. People who have certain genes may also be more likely to have autoimmune disorders. While genes do play a role, they aren't enough to cause an autoimmune disease on their own. 
• Infections - microorganisms like viruses and bacteria could set off changes that make your immune system attack itself. This may be more likely if you are genetically prone to immune system disease. 

RISK FACTORS : 

• Smoking
• Toxins, such as air pollution or hazardous chemicals
• Female gender or having been assigned female at birth (78% of people with an autoimmune disease are women)
• Obesity

SYMPTOMS :

• Fatigue
• Frequent fever
• General sick feeling
• Joint pain and swelling
• Skin problems, such as redness or rashes
• Stomach pain or digestion issues
• Swollen glands