There has been a lot of research that suggests that the immune system can be severely affected by stress.
Kiecolt-Glaser did an experiment to evaluate the effect of acute stressors on the immune system. She had a group of students who were about to have their medical exams. She took the blood sample one month before the exams and another during the exam period. She measured the NK cell activity to see how the immune system was effected and found that the NK cell activity had dropped significantly in the second blood sample that had been taken shows that stress had caused to lower the efficiency of the immune system and made the students were vulnerable to stress-related illnesses.
Also Marucha et al. conducted a study involving a group of students. Marucha inflicted a punch-biopsy 3 days before an exam and found that the wound took 40% longer to heal when the wound was inflicted during the exam period.
Also if a acute stressors could have such a negative impact on the immune system on chronic stressors where also suspected to have a similar effect. Kiecolt-Glaser conducted a study where a group of married couples were asked to have discussions about their marriage and also of the couples had blisters on their arms. It was found that the groups of couples that had very supportive discussions showed the wound healing process to be much faster in comparison to the people who had an argumentative discussion. Also another researcher observed 90 newly wedded couples for a 24 hours basis and were told to resolve marital conflicts. It was found that large amounts of adrenaline and noradrenaline could lead to suppression of the immune system. Also Evans et al conducted a study involving students that were exposed to both acute and chronic stressors. It was found that the SIG-A concentration which is an antibody had increased in concentration when students exposed to