What Does the Immune System Do? This defense mechanism of our body consists of different organs including the spleen, lymph nodes, thymus and the bone marrow that are primarily involved in producing different types of infection-fighting cells. The function of this defense network of our body is discussed below: Kill Invaders Harmful to Health This defense network of our body thwarts off invasion of various pathogens including the fungi, viruses and the bacteria. A strong immune system, won't allow the pathogens to spread the diseases in the body. Production of White Blood Cells The major function of our defense mechanism is to produce white blood cells, which are referred to as soldiers of the body. They help to destroy foreign invaders (pathogens), in turn maintaining optimal health. These cells play a crucial role to protect our body against infections. Identification of Pathogens Before actually killing bacteria, it should be able to distinguish between the 'good' and 'bad' bacteria, otherwise, it may end up destroying its own body tissues. This job of differentiating foreign particles is also effectively executed by this 'bunch' of soldiers. It is crucial for complete destruction of the pathogens. Notifies Entry of Pathogens With the onset of infection, the immune system responds by increasing the body temperature (fever). This is how our defense mechanism works. When the pathogens travel inside the respiratory tract, the defense network reacts by producing a dry cough, so as to expel them. Thus, our defense mechanism notifies that there is something wrong in the body, indicating use of prescription medicines to eradicate the pathogens. On the whole, optimal functioning of the immune system is very important for greater longevity and better health. A decrease in immunity will surely affect your health. The key to maintain a healthy defense network is to have a nutritious diet and stay away from unhygienic habits like excessive drinking, smoking, and tobacco consumption. Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.