The immune systems is a network of cells
To completely understand how the human body stays well and how it gets sick, one must first understand the immune system and how it does its job of keeping us healthy. Briefly, the immune system is a network of cells and organs that protects the body from the continuous direct attack of bacteria, parasites, viruses, microbes and toxins, that would otherwise cause the human body serious infection and illness.
The immune system is an amazing system of many different components working together with the end goal of fighting off every little mishap, from a scrape or cut, to the many bacteria and viruses mentioned above. The immune system protects us 24/7 from all the invaders trying to take over our body. It does this amazing function and it does it usually unnoticed.
We only notice something wrong when the immune system is weakened. Some of the more common signs of a weakened immune system would be slow wound healing, prolonged infection, repeated infection, inflammation, allergic reaction, fatigue, an overgrowth of organisms, such as oral thrush, candidiasis or vaginal yeast infection.
One of the simplest forms of a weakened immune system is the outbreak of cold sores or the common fever blisters (herpes simplex virus). Another, it has been estimated that healthy adults in our western society have an average of two colds a year. So, if you find yourself having significantly more colds than that, its likely you are having a problem with your immune system.
An easy way to understand the function of the immune system is, the job of the immune system is to tag and identify everything that belong to our body. On the other hand, its job is also to tag and identify everything that doesn't belong to our body and destroy all that doesn't belong ...simple as that!
See, in a healthy body, the immune system, this system of check and balance works very well to maintain health and destroy the invaders that don't belong. However, when the immune system is weakened, it becomes unable to keep up with the task of destroying the invading bacteria, viruses, and toxins that are constantly trying to invade the body. Then, infection and illness become more frequent and there is a greater chance of health problems ranging from the minor fever blisters to cancer.
Now think about this because it's very clear and important. The conditions causing the weakened immune system are cumulative. That is, it doesn't just happen over night. In most cases, what is causing the weakened immune system, has been going on for long time... either by our own choice, or by the choice of others that we allow to make for us. Stop, read that last statement again.
Because in most cases, whether you believe it or not, the person's individual "life style habits" are the major causes of the weakened immune system.