An autoimmune disease is a condition in which your immune system mistakenly attacks your body. As many as 3-5% of the world’s population suffer from diseases of the immune system.

The immune system usually protects the body from the microbes such as bacteria and viruses. When the immune system detects these foreign invaders, it sends an army of battle cells to attack them. Usually, the immune system recognizes the difference between foreign and native cells.

In autoimmune disease, however, the wrong “action” of the immune system occurs, which attacks its own cells and tissues as if it were a foreign body. It releases proteins called auto-antibodies that attack healthy cells. The result is the destruction of one’s own tissues and organs. On the outside, we can see them as inflammation. In the long run, damage to certain own tissues and organs causes problems due to uncompleted tasks that these tissues or organs would otherwise have to perform in the body.

Some autoimmune diseases affect only one organ. For example, type 1 diabetes damages the pancreas. Other diseases, such as systemic lupus erythematosus (SLE), affect the entire body.

What causes the occurrence of autoimmune disease?

Researchers do not know exactly what causes autoimmune diseases. Most experts agree that genetics, diet, infections, and exposure to chemicals can affect the formation.

Autoimmune diseases are controlled by the genes of the individual and the environment (infections and the environment in which the individual lives). In cases of inherited diseases / defects of some key genes, the immune system does not function properly and does not distinguish well between its own and foreign cells and tissues. Usually, such an immune system also does not fight well against foreign bodies, so we have a damaged immune system, that has a weak immunity to infections and at the same time it attacks our own tissues and organs. This means that in most cases it is a combination of specific hereditary traits and environmental circumstances – a person gets a certain infection, against which he reacts somewhat inappropriately and uncontrollably due to his genetic peculiarities.

There are other studies that try to answer what actually causes the onset of autoimmune disease.

The “Western diet” is also one of the risk factors for developing autoimmune disease. Eating foods high in fat, sugar, and processed foods is thought to be linked to inflammation, which could trigger an immune response. However, this has not yet been proven. The 2015 study focused on a specific theory called the hygiene hypothesis. Because of the vaccines and antiseptics, children nowadays are not as exposed to the microbes as they used to be. Due to the lack of exposure, their immune system could overreact to harmless substances.

Why does the immune system attack our body?

Doctors do not know exactly what causes an immune system failure. Nevertheless, some people get autoimmune disease more easily than others.

On average, three-quarters of women suffer from these diseases (often the disease begins as early as 15 to 44 years of age). In some diseases, predominance of women is very pronounced, for example, 10 times more women get autoimmune thyroiditis compared to men, and on the other hand, the same proportion of men and women suffer from autoimmune diabetes or Crohn’s disease.

Some autoimmune diseases are more common in certain ethnic groups. For example, lupus affects more African-Americans and Latinos than Caucasians.

Sources:
1. https://www.healthline.com/health/autoimmune-disorders#common-autoimmune-diseases
2. https://www.nasa-lekarna.si/clanki/clanek/avtoimunske-bolezni-napacna-akcija-imunskega-sistema/
3. http://www.galenia.si/files/Avtoimunske%20bolezni.compressed.pdf