Immune system

Your immune system protects you from intruders such as bacteria and viruses, so you don’t get sick. It’s a very smart system that can recognise, attack and neutralise foreign substances that penetrate your body. This often causes fever, swelling, pain and redness; the signs of inflammation. Sometimes, symptoms can be severe and sometimes, you hardly notice them. Your immune system involves a lot of cells, substances and organs. Together, they make sure that you put a proper defence and that you stay healthy.
However, the immune system does not always function properly; for example, there may be a shortage of certain cells or important parts of the immune system do not function as intended.

This can be due to an autoimmune disease. In that case, your immune system attacks your own tissues. It reacts as if they are foreign substances. This may result in inflammations in your body, without a virus or bacterium present. Examples include juvenile arthritis or IBD, which can be very troublesome.

In some disorders or diseases, important cells are destroyed by the immune system, without you immediately noticing it. You will only be affected by it later. One such example is diabetes, in which important cells in the pancreas no longer work, as a result of which no or insufficient insulin is produced.

If your immune system has a shortage of certain immune cells, your immune system will not work properly and you will be more susceptible to infections through viruses, bacteria and fungi. In the event of an HIV infection, for example, your immune system is impaired due to a shortage of CD4 cells, a special kind of white blood cell.

Diabetes
Diabetes is an autoimmune disease. Your immune system, which mainly acts against pathogens, has an immune response against cells in your pancreas. If those cells are destroyed, you produce insufficient insulin. 

HIV
HIV is a virus that infects and destroys certain white blood cells. These are the very cells that play an important role in your defence against infections and diseases. It causes your immune system to be impaired. 

Thyroid gland
A thyroid disease can be an autoimmune disorder. Your immune system, which mainly acts against pathogens, has an immune response against cells or receptors in your thyroid gland. Your body, therefore, produces too much or too little of the thyroid hormone.