Understanding Your Brain and Stress: What Happens When We’re Stressed?

 

It’s time to talk about our good ol’ buddy stress. For most of us, it seems to cling to us all day every day, no matter how many times you try to part ways. It’s just become a part of us, so much so that we might feel weird or empty without it. But what is stress? What exactly does stress do to our bodies, to our brains? Why is it such a good thing to have sometimes, but other times seems to overwhelm us? It’s time that we learn more about the delicate relationship between our brain and stress.

Understand your brain and stress

Understand your brain and stress

Check your understanding

How much do you know about stress? Take this short quiz to find out!

1. Stress is inevitable.
2. People can choose whether or not to be stressed.
3. Exercise is a good stress reliever
4. Stress is a good for when you need to be motivated
5. We'd all be bored without stress

The biological mechanisms of stress

When we experience a stressor, it sets off reactions in our body to help prepare us to handle it. For example, let’s say you’re camping in the woods for the weekend, and you’re just about head to the tent for the night. All of a sudden, you hear a loud crash, and you turn around to find a huge bear looking through your stuff!

Seeing the bear stimulates your hypothalamus to release two hormones, called corticotrophin-releasing hormone (CRH) and arginine-vassopressin (AVP)CRH travels down to the anterior pituitary and stimulates the release of corticotrophin into the blood stream. Once corticotrophin reaches the adrenal cortex (a gland on top of the kidneys), the adrenal cortex increases the production of cortisol and other hormones called catecholamines. 

Surely this must sound very complicated, but here’s the basic idea. Seeing the bear stimulates the Hypothalamic-Pituitary-Adrenal (HPA) axis, which eventually causes the production of the stress hormone known as cortisol. This hormone causes many changes in our body so that we can properly deal with our stressor.

HPA Axis in stress (via Integrative Theraputics)

Your brain and stress-HPA Axis in stress (via Integrative Theraputics)

Your body and stress

AVP rushes to the kidneys and tells it to make less urine and bring more water back into the body. It also sends signals to our blood vessels to constrict, which raises our blood pressure and allows the oxygenated blood to go where its needed. Cortisol limits the amount of insulin production so that less glucose is stored. It then sends all the glucose it can to the rest of the body, so that it has immediate energy when it goes into the “fight or flight” response. Finally, catecholamines such as epinephrine (adrenaline) work with cortisol to get the heart pumping more blood, faster.

Different types of stress can have different impacts on our body. When stress is prolonged, it can have detrimental effects. Here are just a few:

  • Cortisol suppresses the immune system, so the longer cortisol stays in your system, the more at risk you are of getting colds, infections, cancer, food allergies and gastrointestinal issues.

  • The longer your blood vessels are constricted and your blood pressure is elevated, the more at risk you are for vessel damage and plaque buildup. In other words, you’re much more likely to have a heart attack the more you’re stressed.

  • Cortisol can cause weight gain in many ways. One way is because of the high levels of glucose in the blood and the low levels of insulin. This means other cells that need the glucose can’t get it, so they send signals to your brain to tell you you’re hungry. As a result, you overeat, and the unused glucose is stored as fat.

Your brain and stress

Stress can change neural networks

Prolonged periods of stress can cause increased branching in the amygdala– the fear center of the brain. This means that small, less stressful situations can cause huge rises in cortisol levels. Conversely, the hippocampus– which is responsible for learning, memory, and controlling stress- deteriorates and weakens our ability to control our stress.

Stress can shrink your brain

Studies with rat brains have shown that stress can also cause your brain to shrink. Fewer connections between neurons in the prefrontal cortex inhibit our ability to make decisions and judgments. And because the hippocampus deteriorates with prolonged stress, it can make it harder to learn and remember things.

Stress can be detrimental to mental health

Serious mental health problems can arise from stress because of the chemical imbalances cortisol can cause. Because cortisol can make us feel tired after a while, large amounts can have us feeling low in energy or depressed. In other cases, stress activation can lead to severe feelings of anxiety. In many cases, it can actually influence our personality, causing us to be more irritable, hostile, angry or frustrated.

Since stress is such a big part of our daily lives, its more important than ever to take precautions to protect our brain and our body. For tips on how to reduce your stress, click here.

Jessica is a student studying neuroscience and psychology. She is fascinated with all things people, from the way our brains work to how we think. She is always looking for new things to learn, and is eager to help others be inspired.