What causes your immune system to weaken?

The immune system plays an important role in protecting the body against pathogens such as bacteria, viruses, and parasites. When the immune system is weakened, the body will be very susceptible to infections, so how does the body's immune system work? What causes a weakened immune system?

The body's immune system is a collection of white blood cells, lymphocytes in the blood, lymph nodes, bone marrow and spleen, which have the same job of protecting the body from invading germs. The most important distribution sites of the immune system are in the body's entrances, especially in the respiratory and digestive tracts.
The body's immune system by producing antibodies or destroying itself by destroying enzymes, phagocytosis, and invading agents from outside such as viruses, bacteria, fungi and parasites will be destroyed. reside and destroy, do not cause disease. Any cause of the body's immune system is damaged, no longer ensure this function, it will be called immunodeficiency syndrome.
In fact, the body's own immune system plays a role in keeping the body healthy when exposed to pathogens. The immune system is located throughout the body and involves many types of cells, organs, proteins, and tissues. It is important that the body's immune system be able to distinguish the body's own tissue from foreign tissue. Dead or damaged cells are also recognized and eliminated by the immune system. Immunodeficiency syndrome can occur at any age by various mechanisms. In general, this syndrome can be divided into 2 groups of causes: Innate immune deficiency and acquired immune system deficiency.
People with a weak immune system include: Children under 2 years old, babies born prematurely or with birth defects, elderly people over 65 years old, people with chronic diseases or living in toxic environments.
Causes of a weakened immune system:
Genetic disorders: Abnormalities in the genome inherited from a parent with a weakened immune system also make the child more susceptible to infections than others. Children born to normal parents. Disorders in the production of immune cells such as B-cell deficiency disease, T-cell deficiency, combined deficiency of both B- and T-cell types, phagocytic defects, complement deficiency , hypogammaglobulinemia... and unspecified (idiopathic). Causes of acquired immunodeficiency
HIV/AIDS infection: Unlike other viruses, HIV chooses to parasitic and causes direct damage to the body's immune system. The number of immune cells is severely reduced, the body cannot fight off infections that seem to be very mild, so it is easy to become exhausted and die. Using corticosteroids, anti-rejection drugs, cancer chemotherapy drugs that weaken the immune system; Having diabetes weakens the immune system; Nephrotic syndrome, after splenectomy, malnutrition, and exhaustion also weaken the immune system.