While we might perceive burnout as extreme fatigue, it’s actually a breakdown in the body’s ability to regulate stress.

“Chronic exposure to stress disrupts key brain functions, leading to emotional exhaustion, brain fog and physical depletion,” says Ollis. “With modern digital overload, burnout is more prevalent than ever. Constant notifications, emails and social media overstimulate the brain, keeping the stress response activated long after work has ended. Studies show that constant email notifications and screen exposure trigger the same fight-or-flight response as real threats, keeping your nervous system in overdrive.”

Several things happen in your brain when you experience burnout, including:

Hyperactive amygdala: your brain’s fear centre is constantly on alert, making stress feel more intense and never-ending. It’s like having a smoke alarm blaring every time you toast a slice of bread.
Prefrontal cortex suppression: the part of your brain that handles decision-making and focus becomes overwhelmed, which makes it hard to think clearly or even remember simple things. If you’ve walked into a room and immediately forgotten why, burnout might be the culprit.
Mitochondrial dysfunction: efficient mitochondria (the powerhouses of your cells) keep the brain resilient, regulating neurotransmitters and supporting stress adaptation. But stress drains mitochondria, leaving you feeling completely wiped out and unable to recharge. It’s like your phone battery draining faster than it can charge back up.
Autonomic nervous system imbalance: your body gets stuck in fight-or-flight mode, which messes with your sleep, digestion and immune system. It’s like your nervous system thinks every email is a threat as dangerous as being chased by a bear.

Because burnout is a physiological state, simply removing the stressor (eg working less) isn’t going to have a lasting effect. Instead, Ollis says recovery has to focus on rebalancing the nervous system and restoring depleted energy reserves.

According to Burnout: The Secret To Unlocking The Stress Cycle by Emily and Amelia Nagoski, burnout results from incomplete stress cycles, which is when the stress hormones remain elevated because the body never gets the signal that the threat has passed. Essentially, burnout occurs when the body doesn’t have the opportunity to properly process and release stress.

This explains why after coming back from a holiday, that sense of calm evaporates the moment you step back into the office or take one look at your inbox – simply taking time off doesn’t rewire your brain.

How to overcome burnout without working less, according to a neuroscientist