The Chemistry of Stress

We all know what stress feels like, but do we know what stress really is? Even kids nowadays are sensitive to stress. Since the pandemic, stress has skyrocketed, and we are all affected, globally. Unless you’re a person who thrives on stress (see the next post), you likely experience stress as unpleasant. You can correlate your stress to your stomach issues, your back pain, your anxiety, and all the other physical complaints you have now and in the future. You recognize these things…

But do you know:

  1. What actually happens to your body chemistry during stress?
  2. That your body can be stressed even though your mind isn’t?
  3. The part your adrenals play in response to stress?
  4. How to meaningfully change your stress chemistry (without stressing about it)?

These are concepts worth exploring! It is impossible to live a life with zero stress. However, it’s helpful to understand your own stress chemistry, and how to protect yourself from its harmful effects. This is what we cover here and in the next three posts in this series.

Adrenal fatigue, stress

The chemistry of stress: how it’s supposed to work

When your brain perceives stress, it activates your FIGHT OR FLIGHT response. This process takes place within your nervous system (the sympathetic branch of your autonomic nervous system to be exact), and it signals your adrenals to send out emergency, “take action” hormones called epinephrine and norepinephrine. The release of these first responder hormones affects your whole body:

  • Blood flows to large core muscles and away from hands and feet, digestive system, and reproductive organs. This is so all your energy will be used to fight or flee. Explains cold hands and feet, indigestion and gut issues, and poor circulation to your reproductive organs for healthy cycles and fertility.
  • Heart rate and blood pressure rise and blood sugar and fat mobilize. Explains anxiety, high blood pressure, high cholesterol, and high blood sugar.
  • Blood clotting speeds up to prevent blood loss. May contribute to clotting and blood disorders.
  • Muscles contract for extra speed and strength. Explains chronic muscle tension and pain.

The fight or flight response, and your recovery from it, is a natural part of your biology. You need this robust response to react quickly and effectively if, for example, you had to run from a tiger or lift a car off an accident victim. Now, if the stressor continues beyond 10 minutes, your adrenals make your second responder to crises: the infamous cortisol.

Cortisol is a wonderful steroid hormone that puts out inflammation (think cortisone shots, asthma inhalers, and nasal steroids). Cortisol also helps you wake up and feel alert, and supports your immune system to fight infections.

These initial responses to stress are important and helpful to us! You are meant to mount a stress response, and then recover from it and let your autonomic nervous system return from sympathetic (fight or flight) to parasympathetic (aka feed and breed or rest and digest). This is when you can digest your food well, warm up your hands, feet, and uterus, and make babies.

Sympathetic vs. parasympathetic autonomic nervous system

When stress is too much

When stress is too huge to recover from, or when it’s continuous, you can get stuck in fight or flight mode. Your autonomic nervous system can’t shift back into a parasympathetic state. This is what’s called “sympathetic dominance.” This creates anxious, hyper-aroused, and highly-sensitive people. In this situation, the demand for cortisol production goes way up.

When cortisol is high on a regular basis, it starts working against you. It can cause body and brain inflammation, abdominal weight gain, insulin resistance, menstrual irregularities, and osteoporosis. It stresses the HPA axis (hypothalamus-pituitary-adrenal), and dulls the cortisol receptors on your cells (cortisol resistance). High cortisol causes multi-systemic dysfunction shown in this graphic:

Elevated cortisol long term effects

These are real reasons why you should care about stress chemistry. Don’t stress about it, instead, keep reading on to learn how to get a handle on this. Head over to the next post in this series which is When Your Body is Stressed but Your Mind Isn’t.

Comments or questions? Please add below.

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  1. This helped me realize I had more stress than I recognized. Thank you, Laura! Very helpful!

    1. I’m sorry to hear that you’re experiencing stress Anjali. You are not alone! Stay tuned because I’m going to offer lots of ways to reduce stress later in this series.

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