Psychological stressors supress immune function. If heart rate and blood pressure rise in stressful situations, immune efficiency is also likely to be negatively affected. In such stressful situations, more epinephrine and norepinephrine are released; these hormones supress the action of natural killer cells.
With a suppressed immune system, latent viruses that have been dormant can emerge, and trigger attacks of common viruses like shingles and herpes simplex. As a result, immune cells can become impaired.
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