Psychoneuroimmunology and Stress

Science of Psychoneuroimmunology

Psychoneuroimmunology is defined as the examination of the interactions among psychological, behavioral, and social factors with immunological and neuroendocrine outcomes. It is now well established that psychological factors, especially chronic stress, can lead to impairments in immune system functioning in both the young and older adults. In several studies of older adults, those who are providing care for a relative with dementia report high levels of stress and exhibit significant impairments in immune system functioning when compared with noncaregivers. Stress-induced changes in the immune system may affect a number of outcomes, including slowing the wound healing process and increasing susceptibility to infections.

What is stress?

Stress is a feeling you get when faced with a challenge. In small doses, stress can be good for you because it makes you more alert and gives you a burst of energy. For instance, if you start to cross the street and see a car about to run you over, that jolt you feel helps you to jump out of the way before you get hit. But feeling stressed for a long time can take a toll on your mental and physical health. Even though it may seem hard to find ways to de-stress with all the things you have to do, it's important to find those ways. Your health depends on it.

Chronic Stress

We all have stress sometimes. For some people, it happens before having to speak in public. For other people, it might be before a first date. What causes stress for you may not be stressful for someone else. Sometimes stress is helpful—it can encourage you to meet a deadline or get things done. But long-term stress can increase the risk of diseases like depression, heart disease and a variety of other problems. A stress-related illness called post-traumatic stress disorder (PTSD) develops after an event like war, physical or sexual assault, or a natural disaster.

If you have chronic stress, the best way to deal with it is to take care of the underlying problem. Counseling can help you find ways to relax and calm down. Medicines may also help.

How Stress Affects your Health and What You Can Do About It

Stress—just the word may be enough to set your nerves on edge. Everyone feels stressed from time to time. Some people may cope with stress more effectively or recover from stressful events quicker than others. It's important to know your limits when it comes to stress to avoid more serious health effects.

Stress can be defined as the brain's response to any demand. Many things can trigger this response, including change. Changes can be positive or negative, as well as real or perceived. They may be recurring, short-term, or long-term and may include things like commuting to and from school or work every day, traveling for a yearly vacation, or moving to another home. Changes can be mild and relatively harmless, such as winning a race, watching a scary movie, or riding a rollercoaster. Some changes are major, such as marriage or divorce, serious illness, or a car accident. Other changes are extreme, such as exposure to violence, and can lead to traumatic stress reactions.

How does stress affect the body?

Not all stress is bad. All animals have a stress response, which can be life-saving in some situations. The nerve chemicals and hormones released during such stressful times, prepares the animal to face a threat or flee to safety. When you face a dangerous situation, your pulse quickens, you breathe faster, your muscles tense, your brain uses more oxygen and increases activity—all functions aimed at survival. In the short term, it can even boost the immune system.

However, with chronic stress, those same nerve chemicals that are life-saving in short bursts can suppress functions that aren't needed for immediate survival. Your immunity is lowered and your digestive, excretory, and reproductive systems stop working normally. Once the threat has passed, other body systems act to restore normal functioning. Problems occur if the stress response goes on too long, such as when the source of stress is constant, or if the response continues after the danger has subsided.

How does stress affect your overall health?

There are at least three different types of stress, all of which carry physical and mental health risks:

  • Routine stress related to the pressures of work, family and other daily responsibilities.
  • Stress brought about by a sudden negative change, such as losing a job, divorce, or illness.
  • Traumatic stress, experienced in an event like a major accident, war, assault, or a natural disaster where one may be seriously hurt or in danger of being killed.


The body responds to each type of stress in similar ways. Different people may feel it in different ways. For example, some people experience mainly digestive symptoms, while others may have headaches, sleeplessness, depressed mood, anger and irritability. People under chronic stress are prone to more frequent and severe viral infections, such as the flu or common cold, and vaccines, such as the flu shot, are less effective for them.

Of all the types of stress, changes in health from routine stress may be hardest to notice at first. Because the source of stress tends to be more constant than in cases of acute or traumatic stress, the body gets no clear signal to return to normal functioning. Over time, continued strain on your body from routine stress may lead to serious health problems, such as heart disease, high blood pressure, diabetes, depression, anxiety disorder, and other illnesses.

Stress and Stressors

Even though there is little consensus among psychologists about the exact definition of stress, mainstream scientists define stress as the process by which we perceive and cope environmental factors that are appraised as threatening or challenging by our brains. Those factors, known as stressors, could be either physical or psychological in natural. A stressor can be the presence of flood after a storm or nervousness about SATs. According to the theory of Richard Lazarus, a psychologist from UC Berkeley, there are three types of stressors (also known as stimuli): major cataclysmic changes that affect large numbers of persons; major changes affecting one or several persons; and daily hassles. (Lazarus, 1984)

The first type of stressors may refer to phenomena that are outside anyone’s control. Like natural disasters, wars or uprooting and relocation, they are universally stressful. The stressors themselves could be ephemeral, but the physical and psychological aftermath is long-term. The second category of stressors happen to relatively few people or to individuals. These are events out of the individual’s control, like the death of loved ones, a robbery, or the process of taking exams. The daily hassles are little things that distress or irritate: a quarrel with parents, a losing sports game or too much homework.

The above listed stressors all seem to have negative effects and impacts to our life, however, stressors can be positive as well. According to Hans Selye, the father of stress study, there are two types of stress: eustress and distress. Eustress refers to stress that actually allows the body to function as well or better than it does while unstressed.

Learning Activity

  • Go to Stress Assessment to rate your own stress level.
  • Were the results what you expected? Why or why not?






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