What stress does to your brain and body

• If you're feeling tired, fuzzy, or unmotivated, you're not alone.
• Stress related to the coronavirus and the global pandemic can take a huge short- and long-term toll on your mental and physical health.
• The wear and tear it causes our bodies is called allostatic load, which can include things like depression, irregular menstrual cycles, and increased susceptibility to disease.
• Here's what's happening in your brain when you're chronically stressed and what it does to your body.

Following is a transcript of the video.

Abby Tang: How are you feeling?

Graham Flanagan: I literally played that song, ♪ You had a bad day ♪

Alex Appolonia: I wrote down some points because my brain is like mush lately.

Fran Lam: Sad, worried, stressed.

Victoria Barranco: Physically, like all of the negative emotions.

Abby: This probably sounds super familiar, and that's because a lot of us are feeling stressed right now. But this isn't normal stress. This is pandemic stress, and it is messing with our brains in a very specific way.

When you get stressed, it triggers a chain reaction that starts in the amygdala, your emotional-processing headquarters. Your eyes and ears send info to the amygdala, and it determines if what you're seeing and hearing is stressful. If it is, it sends a signal to your command center, the hypothalamus. It's in charge of getting the word out to the rest of your body by way of the autonomic nervous system.

The adrenal glands get the message first and pump adrenaline into your bloodstream. Your heart beats faster; you breathe more rapidly because your muscles need extra blood and your brain needs extra oxygen. They're preparing to react to whatever threat is causing your stress response. All of this happens in the blink of an eye. It's like how people can jump out of the way of a car without really thinking about it.

The emotional amygdala basically overrides your prefrontal cortex, the part of your brain where all the logic happens. So you don't get a chance to think things through; you just react. Once the threat dies down, though, the parasympathetic nervous system takes over and returns all those heightened reactions to normal. But if the brain still detects danger after the initial adrenaline rush, the hypothalamus sends out another message to the rest of the HPA axis. This triggers another series of hormones that lead to the release of cortisol, which signals to the body that it needs to stay on high alert and keep pumping out stress hormones.

Right now for a lot of us, that threat is still very much alive. The amygdala is still overriding the prefrontal cortex, which is in charge of decision making and planning. So those feelings of forgetfulness and tiredness, they're likely a product of this stress response that won't turn off. Stress hormones and the accompanying bodily responses are super helpful in the short term, but our bodies aren't meant to function in this heightened state for weeks or months at a time. And over time, your brain will burn out.

When it does, it can lead to something called allostatic load, the cumulative wear and tear that happens to your body when you're dealing with chronic stress. A high, prolonged level of cortisol can mess with a lot of stuff. It's even been seen to decrease the volume of your hippocampus, the area responsible for learning and memory, and a reduced hippocampus is more often seen in people with depression than those without.

So all this is to say that the extra stress is probably not doing your brain or your body any favors. And humans are historically really bad at making decisions when they don't know what's going to happen. So, what can you do to reduce allostatic load? Reduce stress. Eating well, exercising, and maintaining a regular sleep schedule cannot be overlooked. Exercising alone can reduce stress hormones, even with just a 20-minute walk.

And a different way of thinking could also help us: an idea called model-free learning. It's basically trial and error. Instead of basing your risk assessment on similar examples from the past or envisioning future scenarios, you just take it one step at a time. This way, you reassess and update your own estimate of what's happening and how to prepare.

We're dealing with a new virus, constantly changing policies, and likely a completely different schedule and maybe even environment. Our brain is on high alert at all times to identify potential threats. Which means that even if you're spending most of your time laying around, your brain isn't, so try not to beat yourself up for feeling tired or fuzzy or unmotivated. You just don't need anything else to stress about.

Now that you know all of this, how are you feeling?

Alex: To be honest, I do still feel the same.

Fran: I think I'm feeling a bit better after watching it.

Victoria: It's actually my body is exhausted from feeling things and being under stress all day, all the time.

Graham: Whenever I feel that allostatic load starting to weigh down on me, you know, I can put a name on it, a face on it, and it makes it a lot easier to deal with it.