The field of studies the effects of psychological factors such as stress, emotions, thinking, and behavior on the immune system.

Psychoneuroimmunology

Explanation:

Psychoneuroimmunology is a branch of psychology that is also known as or . It is often abbreviated into PNI. It focuses on studying how the immune system is affected by psychological states, as observed by neurological processes in the nervous systems.

History has shown that many scientists point out that there may be a link between negative emotions and how people can the immune system gets compromised due to it. An example would be how people with higher stress levels are prone to experiencing flu, or other viral diseases more than people with lower stress levels.