Feeling Sick? It Means Your Immune System is Fighting Back

Billions of individual viruses must fight the immune system, before they can spread to complete the infection. The struggle inside the body causes the most symptoms.

The first stop for invading virus particles is cells in the nose and throat mucosa. The virus takes over the production apparatus inside the cells, which is used to make new virus particles that can spread the infection to other respiratory system cells. But the invasion does not take place without a fight.

When virus hits a cell, sensitive proteins on the surface immediately react to the alien appearance of the virus. The proteins send a warning about the attack to the cell’s interior, and a cloud of toxins are fired in the opposite direction.

Moreover, the cell sends a signal, which activates white immune system blood cells. T cells and natural killer cells poison the infected cells, preventing virus from propagating and spreading the disease. If the body was previously infected with the same type of flu, it already has a formula for antibodies that can stop the virus. But if the virus type is unknown, the struggle will continue for a longer time, as the body must first invent a new antibody suited for the invading virus.

This defensive action is stressful for the body, causing symptoms such as a running nose, fever, and pain. The disease has broken out.