When you start feeling overwhelmed, your hippocampus is probably already taking the hit. The hippocampus, by the way, is the region in charge of transferring bits of information from short-term memory storage to long-term memory. It’s one of the parts of your brain that makes learning possible. And here’s the kicker: when you’re stressed, it disconnects from your frontal lobe, the rational centre that helps you make calm, reasonable decisions. The frontal lobe is the computer you use when you decide to say “screw it” and order another beer. Or when you decide to drive after those seven beers. That’s how important it is.
What happens in the brain under stress
When you face a stressful situation, your body activates the hypothalamic–pituitary–adrenal axis, which releases cortisol and adrenaline, and suddenly everything turns into a party and your body goes full Chernobyl mode. These hormones prep your body for fast reactions, but they also mess with your brain chemistry and structure.
Adrenaline “increases heart rate, constricts blood vessels, dilates air passages, and participates in the fight-or-flight response of the nervous system.” The main functions of cortisol are to “increase blood sugar levels through gluconeogenesis, suppress the immune system, and help metabolise fats, proteins, and carbohydrates.” That’s what Wikipedia says, not me.
Too much cortisol reduces the efficiency of synaptic connections in the hippocampus, making it harder to store and retrieve memories. Meanwhile, the amygdala (the drama queen responsible for intense emotions) takes over and shuts out the rational parts of the brain. Basically, you turn into a gazelle spotting a lion: completely terrified and not exactly stopping to analyse the topography before deciding which way to run. You just bolt, because otherwise you might not live to regret it. That’s what happens under high stress: you panic and make terrible decisions. Remember: the seventh beer.
Why the hippocampus disconnects from the frontal lobe
Normally, the hippocampus and the prefrontal cortex work as a team: one provides context, the other plans ahead. But when stress levels rise, that connection goes out the window. The brain switches to survival mode, and deep thinking is no longer a priority. That’s why, under pressure, you forget simple things or can’t focus. It’s not lack of discipline or you being dramatic: it’s straight-up neurobiology.
When the connection between these two areas weakens, you’ll struggle to concentrate (hello again, gazelle), to learn, and to control your emotions and impulses. And if you stay stressed for too long, the brain (being “plastic,” meaning it changes and adapts to what’s happening) starts shrinking your hippocampus. Over time, you’ll remember less, pay less attention, and basically be less alive to what’s going on around you.
What to do about stress
Honestly? I have no idea. If I did, I’d bottle it and get rich.
What I do know is that it takes consistency. Sleeping enough lets neurons repair their connections. Regular movement improves blood flow and stimulates the creation of new neurons. You don’t need to become a runner; walking places is enough. Short breaks during the day lower cortisol, especially if you drop your phone and, I don’t know, turn on the TV. Or call someone and say you’re totally freaking out and need to talk about anything: gossip works great in these situations because you shift your focus somewhere else. You can also see a doctor. Or someone who actually knows what they’re doing. Not everything can be fixed with exercise; sometimes you have to ask for help.
Trying to calm yourself down, chanting Instagram mantras (or whatever nonsense blogs push), or forcing yourself to relax alone isn’t always enough. A brain under stress might be too blocked to self-regulate. Asking for help isn’t weakness, it’s doing what needs to be done. Talking to someone you trust can give you the perspective, strategies, and support that no breathing technique or viral advice can replace. And if your doctor says you need a benzodiazepine, maybe just listen.
And yes, when you’re stressed, the last thing you feel like doing is staring out the window with a cup of tea or booking a therapy session, especially if you can’t afford it. You’re absolutely right. It’s easy to say, impossible to do when you’re drowning or broke. And yeah, I sell advice I can’t always follow myself.
At the end of the day, it’s important to remember that stress isn’t just an annoying feeling: it changes brain chemistry and messes with the connections between its parts. The hippocampus and frontal lobe stop talking, and that’s a disaster. But neuroscience actually has good news. Talking about “neuroscience” already makes me sound like a first-class idiot, but whatever. The point is: sleep well, walk a bit, have drinks with your friends, watch reality shows, it all helps. Honestly. Sometimes not enough, but it usually helps.
And one last thing, from experience. The world won’t stop. Life keeps going. The more stress you carry, the less you actually live. Stress can kill you while you’re still alive. Take care of yourself, please. And if you need help, ask for it.
I try too, but I’m not great at it.
The original version of this text is here (in Spanish).