Does stress damage the immune system? That question can only be answered by first discussing the difference between acute (short-term) stress and chronic (long-term stress). While acute stress causes responses in the body that include boosting the immune system, chronic stress may impair the immune system.
Better questions are "Does stress damage the immune system on the short term?" and "Does stress damage the immune system on the long term?" The body's response to acute stress (a real or immediate threat such as a confrontation with a burglar) which is sometimes called the "fight or flight" response includes changes in all the systems of the body. Since the question is "Does stress damage the immune system?", then we will focus on those responses to acute stress that are temporarily boosting the immune system during this flight or flight scenario.
The most noticeable initial response to the burglar's appearance is an increase in heart rate. Your body is preparing itself for the possibility that you will need to run. The increase in heart rate triggers the spleen to discharge more red and white blood cells. The red blood cells increase your oxygen supply, while the white blood cells will be necessary for boosting the immune system, in case you fall or the burglar attacks you. Portions of the brain trigger the production and release of cortisol, a primary stress hormone, which dampens less important parts of the immune system, so that white blood cells and other infection fighters can be directed to the areas of the body where injury or infection are most likely to occur, namely the skin, bone marrow and lymph nodes, thus effectively boosting the immune system temporarily. Once the immediate danger has passed, the body systems return to normal.
So, the answer to "does stress damage the immune system" on the short-term is "no". Acute stress activates the body's natural defense systems and while this results in boosting the immune system temporarily, it does not "damage" the immune system. Chronic stress, however, is a different story.
Does stress damage the immune system on the long term? It can, if persistent stressful situations, such as a high-pressure job or an unhappy relationship, do not allow the body to return to a normal relaxed state. Instead of boosting the immune system, chronic stress appears to blunt the immune response, increase the risk for infections and impair a person's response to immunizations. Studies have shown that people under chronic stress have lower than normal white blood cell counts, are more vulnerable to colds and other viruses, take longer to recover from them and experience worse symptoms than people who do not have high stress levels.
If you are concerned about the answer to the question; does stress damage the immune system, then you may feel that you are in a stressful situation over which you have no control. It may not be possible to leave a high-pressure job in order to reduce your stress level and if doing so would cause financial problems, you could actually increase your stress level. Good nutrition, regular exercise and certain health supplements may help you protect yourself from the effects of chronic stress by naturally boosting the immune system and allowing the body to return to a more relaxed state.Source: http://www.healthguidance.org/authors/472/Patsy-Hamilton