What is Immune System The immune system is the body’s defence mechanism – the army with which the body protects itself against disease-causing organisms such as viruses, bacteria or fungi, which are known as pathogens. The troops that make up this army are various types of white blood cells, which are produced in the bone marrow. When working well, the immune system is constantly vigilant in order to protect us from infection, infestation and general invasion by bugs of all descriptions but, there are many causes that will ruin it and make you sick and it may kill you if you take it easy. In the following below I am going to mention some of the causes that ruin your immune system and you should avoid those habits immediately if you want to have a good immunity. 1. Being Stressed Chronically: Stress defined as a state of mental tension and worry caused by problems in your life, work and other areas . It’s also a very real cause of many health problems. ...