Part 1: What everybody ought to know about stress

What is stress and how does it affect health?

Would you agree that right now life feels more hectic and stressful than ever? That there are fewer times when you feel amazing in-the-moment clarity and confidence and all appears to be going well? And when those clear and confident times happen, do they seem to pale in comparison to the times when you’re really feeling the pressure? Do these stressful times when life seems too demanding and it feels like there are too many things to worry about, and you simply can’t function like your very best self come around too often for too long? This article goes over some of the benefits and risks of stress and the physical and mental effects it can have on our health.

Everyone can identify stress—when situations feel overwhelming and it gets hard to cope well. And if you’re like me, you might agree that now is definitely one of the most stressful times we’ve had.

Before we dive into all of the negative effects of stress, let’s acknowledge that it can have some benefits. On one hand, stress can motivate you to accomplish goals, like becoming more alert and efficient so you meet deadlines. That’s especially true for short-term stress. But too much stress over too long of a timespan has negative consequences on your mental and physical health. These can impact how well you can emotionally handle life’s curveballs and your relationships, and can affect your eating, sleeping, and fitness patterns. Stress can even increase your risks for short-term—or even long-term—health issues.

According to the Canadian Mental Health Association, stress is “our body’s response to a real or perceived threat.”[1] According to the National Institute of Mental Health, “stress is how the brain and body respond to any demand.”[2] Stress isn’t the situation (or “stressor”) itself, but rather stress is the reaction to that threat or demand. It happens when you feel threatened or when the demands on you are greater than your ability to deal with them.[1] 

Stress is a reaction to a situation or “stressor”

Let’s take a second to unpack the fact that stress is the reaction to a situation or “stressor.” It’s true that not everyone has the same response to the same situation—some things that stress me out may not stress you out. For example, if you love the adventure of moving to a new home or city, it won’t stress you out as much as it would for someone who loathes packing up. Plus, everybody’s responses to stressors can be slightly different. Sometimes when two different people are equally stressed, one may be able to manage and recover more effectively than the other.[2] In other words, how we experience stressors can be unique, even if the biological stress response is the same.

Stressors come in all shapes and sizes, too. Some of the biggest stressors are significant life events, like changing jobs, divorce, or the death of someone you care about[1], or they can be traumatic events like a natural disaster, war, or assault.[2] Other stressors can come from day-to-day life, like parenting, dealing with a chronic illness, or being a caregiver.[1,3] Some stressors are even smaller, like traffic on your way to work or school, or “spilled milk.”[1] 

DISCLAIMER: If you are dealing with trauma or a serious mental health issue, please see a medical or mental health professional.

The most important thing to know is that stress is your body’s completely normal way of trying to protect you. There are several strategies you can use to cope with it. This article goes over some of the impacts that stress can have on your life, the biological basis for it, and several uncommon ways to deal with stress.

The normal stress reaction

When a situation stresses you out, it’s because your body and mind are instinctively trying to help you survive that stressful threat or demand. This prioritizes the “threat” above everything else and activates your biological fight, flight, or freeze reactions.

Fight – Stress can put your brain on “high alert,” make you feel frustrated or angry, increase your heart rate and breathing, and tense your muscles.[2]

Flight – Stress can motivate you to run away, procrastinate, or avoid the problem altogether.

Freeze – Stress can make you feel overwhelmed and unable to focus or concentrate on anything—including a solution to the stressor.

However, many of the stressful situations that activate these natural survival mechanisms don’t actually threaten your survival. Of course, there are exceptions—reacting to a natural disaster, war, or assault may very well be for survival. The problem is that your body reacts in the same way when you’re facing a less threatening, but equally stressful situation like a job change, short deadline, parenting issues, or a traffic jam. In these cases, your normal biological reaction may be a bit too intense for the reality of the situation—and it’s not your fault! There are biological mechanisms in place that I’ll share with you in Part 2. And so fighting, fleeing, or freezing is often not a useful strategy to deal with “every day” demands that most certainly are stressful but don’t in fact threaten your survival. But biologically, your natural reactions don’t distinguish between the two. 

The 2 types of stress (acute and chronic)

Acute stress is usually very high but very short-lived. An example might be swerving to avoid a collision. In this case, the mind goes into “high alert” stress mode and the body uses instant reflexes for a short time—sometimes just seconds or minutes—and then can start relaxing after the stressor is gone so you can continue on with your day.

Chronic stress, on the other hand, is long term. Dealing with a drawn-out legal issue, for example, or a disease that goes on for months and even years can become a legitimate cause of chronic stress. This type of stress is particularly harmful because it keeps your body and mind on “high alert” all the time without giving it the opportunity to relax and get back to normal functions like resting and digesting.[B]

Stress’s effect on mental health

When you’re feeling stressed you may notice that it affects your mood and attention. You may feel irritable, worried, sad, angry, or otherwise unable to focus in a rational and calm way.[3] Stress can also lead to more serious mental health issues like depression or anxiety.[2,3,4]

Stress’s effect on physical health

Over time, your natural physical reactions to stressors can become chronic and can impact many of your body’s systems and healthy functions. Stress can negatively affect your digestion, immune, cardiovascular and reproductive systems.[1,2,4] This can lead to many symptoms such as digestive distress, headaches, muscle tension, impaired sleep, or weight gain or loss.[1,2,3,4] Stress can also increase your risk for conditions such as asthma, obesity, heart disease, and high blood pressure.[3,5,6] 

You can see that stress can have so many different and seemingly unrelated health effects. Stress can impact your mental and physical health in several ways. In the next part, we’ll talk about how these effects are even possible—which becomes clear when you understand the biology of stress.

Stay tuned for Part 2 on the biology that underpins the multitudes of mental and physical effects of stress!


1 – Canadian Mental Health Association. (2016, February 28). Stress.

2 – National Institute of Mental Health. (n.d.). 5 things you should know about stress.

3 – US Department of Health and Human Services Office of Disease Prevention and Health Promotion. (2021, June 10). Manage stress. My healthfinder.

4 – National Center for Complementary and Integrative Health. (2020, January). Stress.

5 – Conversano, C., Orrù, G., Pozza, A., Miccoli, M., Ciacchini, R., Marchi, L., & Gemignani, A. (2021). Is Mindfulness-Based Stress Reduction Effective for People with Hypertension? A Systematic Review and Meta-Analysis of 30 Years of Evidence. International journal of environmental research and public health, 18(6), 2882.

6 – Bouillon-Minois, J. B., Trousselard, M., Thivel, D., Gordon, B. A., Schmidt, J., Moustafa, F., Oris, C., & Dutheil, F. (2021). Ghrelin as a Biomarker of Stress: A Systematic Review and Meta-Analysis. Nutrients, 13(3), 784.

7 – Mayo Clinic. (2021, July 8). Stress management.

8 – Scholarpedia. (2013, August 17). Nervous system.,the%20brain%20and%20spinal%20cord

9 – Heaney J. (2013) Hypothalamic-Pituitary-Adrenal Axis. In: Gellman M.D., Turner J.R. (eds) Encyclopedia of Behavioral Medicine. Springer, New York, NY.

10 – Welt, C. (2019, April 30). Hypothalamic-pituitary axis. Up To Date.

11 – Bhutani, S., vanDellen, M. R., & Cooper, J. A. (2021). Longitudinal Weight Gain and Related Risk Behaviors during the COVID-19 Pandemic in Adults in the US. Nutrients, 13(2), 671.

12 – Roos, L. E., Cameron, E. E., & Mota, N. (2020, December 15). Beyond self-care: Try these 5 therapeutic tools to manage stress better during COVID-19 restrictions. The Conversation.

13 – Worthen M. & Cash E. (2020, August 29). Stress Management. StatPearls Publishing. Available from:

14 – Zhang, J. Y., Cui, Y. X., Zhou, Y. Q., & Li, Y. L. (2019). Effects of mindfulness-based stress reduction on prenatal stress, anxiety and depression. Psychology, health & medicine, 24(1), 51–58.

15 – Bemanian, M., Mæland, S., Blomhoff, R., Rabben, Å. K., Arnesen, E. K., Skogen, J. C., & Fadnes, L. T. (2020). Emotional Eating in Relation to Worries and Psychological Distress Amid the COVID-19 Pandemic: A Population-Based Survey on Adults in Norway. International journal of environmental research and public health, 18(1), 130.

16 – Canadian Society for Exercise Physiology. (n.d.). 24-hour movement guidelines for adults.

17 – Fletcher, B. D., Flett, J., Wickham, S. R., Pullar, J. M., Vissers, M., & Conner, T. S. (2021). Initial Evidence of Variation by Ethnicity in the Relationship between Vitamin C Status and Mental States in Young Adults. Nutrients, 13(3), 792.

18 – Public Health Agency of Canada. (2018, October 12). Cannabis and your health: 10 ways to reduce risks when using.

19 – Aeon, B., Faber, A., & Panaccio, A. (2021). Does time management work? A meta-analysis. PloS one, 16(1), e0245066.