How can the immune system be damaged?

Some of the more common disorders and diseases that damage the immune system include:

• Allergies: An allergy is the body’s overreaction to a harmless, nontoxic substance. In the presence of the nontoxic substance, the immune system overreacts and releases histamines, which trigger allergy symptoms. These may range from mild stuffiness and sneezing or more severe breathing problems. 
• Autoimmune disorders: Autoimmune disorders occur as a result of the immune system attacking its own healthy cells. Examples of common autoimmune disorders include diabetes, rheumatoid arthritis, Hashimoto’s disease, and lupus.   
• Primary immunodeficiency disorders: Immunodeficiency disorders are inherited conditions. They prevent the immune system from working as it should, making the individual more vulnerable to infections and certain diseases.
• Infectious diseases: Infectious diseases are the result of germs entering the body, replicating and causing damage. Two of the most well-known infectious diseases, HIV (human immunodeficiency virus) and mononucleosis, weaken the immune system and lead to serious illness.  
• Cancer: Certain types of cancer, such as lymphoma, leukemia, and myeloma, occur due to uncontrollable growth of immune cells. These cancers affect the immune system directly, compromising its ability to function as it should. 
• Sepsis: Sepsis is an extreme response of the body’s immune system to an infection, in which the immune system attacks and destroys healthy tissues and organs, triggering widespread inflammation throughout the body that can result in organ damage, organ failure, and death. 

The immune system can also be damaged by certain lifestyle habits such as: 

• Lack of sleep
• Anxiety
• High fat diet 
• Not enough fresh fruits and vegetables
• Too much processed foods
• Lack of exercise
• Low vitamin D
• Too little time spent outdoors
• Smoking
• Excessive alcohol intake
• Certain medications