Learn How Stress Impacts Your Immune Function

Stress is unavoidable and plays a big role in your life. Some stress can be good—motivating you to accomplish your goals and complete necessary tasks. But a lot of stress is bad, leaving you feeling overwhelmed, even sick. That’s because the negative effects of stress on immune function are significant.

Think about your life. Feeling good and being stressed don’t usually happen at the same time, right? That’s because stress on your body and mind can weaken your immune system. Why is that? Your body goes into overdrive so you can perform at maximum power to tackle your stressors, meaning the strength of your immunity can suffer.

Even though that’s very simplified, it’s a good start to a deeper conversation about how stress impacts immune function. First, you’ll want to understand the way your body responds to stressors so you can see how stress and immunity are connected. Then you’ll learn ways to improve your reaction to stress to help keep you feeling healthy through difficult times.

The Language of Stress

Learning some of the terminology used to talk about stress will give you a better grasp of your body’s natural responses. Here are the basics:

  • Stressor: Any stimulus that causes stress. There are two kinds of stressors: physical and psychological. Physical stressors are stress on the body. Psychological stressors are stress on the mind.
  • Hypothalamus: An important command center in the brain. This region is about the size of a penny and sits in the middle of the brain. It controls the activity of the pituitary gland and regulates hunger, thirst, sleep, body temperature, and many emotions.
  • Pituitary Gland: The master gland responsible for releasing most of the hormones in your body.
  • Adrenal Glands: Triangular glands that rest above the kidneys that are responsible for releasing cortisol.
  • Cortisol: The primary hormone released into the blood in response to stress.

How Your Body Handles Stress

Your body has a built-in response protocol that springs into action every time you experience stress. It begins when a stressor comes along and puts pressure on your mind or your body.

The part of your brain that recognizes stress is called the hypothalamus. As soon as the hypothalamus recognizes a stressor, it sends a message via neurons to a neighboring region of the brain called the pituitary gland. This gland registers signals from the hypothalamus and tells the adrenal glands (above your kidneys) to increase the amount of stress hormones circulating in the blood.

That’s the basics of your body’s natural stress response. To understand it further and connect the dots between stress and immune function, let’s explore your primary stress hormone—cortisol.

This important hormone works by providing an energy boost during periods of stress. But the effects of cortisol are temporary. Once the stress wears off, so does the energy assistance.

Another way cortisol helps your body manage stress is by powering down any non-essential operations in the body. Unfortunately, some of your immune functions are put on pause thanks to cortisol. It does this in an effort to conserve energy while under stress, but this makes stressful periods the perfect time for germs to settle in.

How Stress Impacts Your Immune Function

Cortisol works temporarily when the stressor you experience is short-lived, like running late for an appointment or competing in a triathlon. That makes the impact on your immunity minimal. But when stress lasts longer, like days or weeks, increased cortisol levels can start to have more negative effects.

Elevated cortisol suppresses your immune system by reducing production of white blood cells. Without white blood cells on the hunt for germs, your response to an infection is much slower. So, long periods of cortisol elevation can leave you susceptible to illnesses you otherwise wouldn’t succumb to. That’s why it’s common to come down with a cold after a period of high stress.

College students preparing for final exams provide a good example. Many students find they develop a cold in the days following the end of a college term. But why?

The stressor (final exams) initiates their bodies’ stress response. Cortisol levels rise and stay elevated for a longer period while they study—maybe even for a few weeks. During this stressful time, their immune systems are suppressed so their brains can harness as much available energy as possible to tackle the stress in the form of final exams.

Running at this low capacity provides germs an easy opening to infect healthy tissue and bring on illnesses like the common cold. And the symptoms, which are partly felt as part of your immune response, come on once those stressful tests have passed.

College tests aren’t the only kind of long-term stress, of course. You may notice a similar pattern in your own life. Moving to a new city, having a baby, changing jobs, and other life challenges are all common long-term stressors. And since any prolonged stress elevates cortisol levels and suppresses immunity, germs can exploit your weakened immune system in these times of intense pressure.

Alleviate Stress for Immunity’s Sake

Learning to manage the stress in your life can help keep cortisol levels down and protect your immune system. There are many activities you can try that bust through stress and are good for your overall health, too.

Meditation is one of the most effective stress-management strategies. Just a few minutes concentrated meditation daily can significantly reduce blood cortisol levels and help you feel peaceful and serene. It can help support your immunity, too.

In one study, researchers found people who meditated every day developed more antibodies to a flu virus than those who didn’t. So, spend a few minutes every day disconnecting from the busy world and especially turn to meditation when you feel stressed.

Exercise is another tried-and-true way to alleviate stress. You already know many of the benefits of moving your body every day. Now you can add stress-relief to the list. (Check out this story for even more options for dealing with stress.)

If none of the lifestyle remedies work, a conversation with a mental-health professional should be your next step. Talking with a counselor or social worker in a therapy setting can help you confront the stressors in your life and find effective methods for managing them.

No matter your choice of stress-management technique, it’s time to better equip yourself to protect your body—and immune health—from the effects of stress.