Combating cold symptoms takes time, but your immune system will get it under control. Taking a moment to understand how your immune system takes on a cold virus early on is your first step to navigating through cold and flu season.
The Role of the Immune System
The human body's immune system is extremely complex, and is still not yet fully understood by scientists. The main function of the immune system is to defend the body against foreign substances, including viruses, bacteria, and fungi. Various organs and cells are involved in combating the infiltrators – and the enemies within – including the bone marrow, lymph nodes and tissue of the respiratory tract, the digestive tract, the lungs, and the urinary tract, as well as the spleen, liver, and thymus gland.1
The Role of a Cold Virus
The common cold is a self-limiting viral infection of the upper respiratory tract that almost always runs the same course. The incubation period is about 24 to 72 hours. Cold symptoms such as a tickly nose, the urge to sneeze, and a scratchy throat are usually the first tangible signs (at this stage, “First Defence” products can help stop the cold in its tracks and keep it at bay).
If the immune system does not manage to fend off the viruses at this stage, it is not long (typically one to three days) before the tickle intensifies and the scratchiness becomes a sore throat. There is often an urge to cough, which can lead to painful fits of coughing, though throat drops and cough suppressants may relieve some of these symptoms. High fever is rare in adult cold sufferers, but is frequent in children. After one to three days, the discharge in the bronchial tubes and nose becomes thick and the dry cough becomes productive. The typical cold takes an average of seven to ten days – and in some cases up to three weeks – to wear off completely. The cough is often persistent and may last longer than other symptoms.2 Many of these common cold symptoms may be relieved by taking a cold medicine.
After recovering from the cold, the immune system builds up antibodies to defend itself from catching that particular cold virus again. However, given that there are over 200 strains of cold viruses, the immune system is still susceptible to other strains.
1 Schindler, LW, Understanding the Immune System, Diane Publishing, 1991: 3-4.
2 Heikkinen, T, Järvinen, A, The common cold, the Lancet, 4 January 2003; 361: 51-58.16