You’re in a restaurant during a busy Friday lunch service. The music is too loud, the lighting is too bright, multiple conversations are happening around you, and someone at the next table has ordered something particularly aromatic. You feel an urge to leave that has nothing to do with the food. That, in all likelihood, is overstimulation.
What overstimulation actually is
Overstimulation, sometimes called sensory overload, is a physiological response to the brain receiving more sensory input than it can efficiently process at once. Sight, sound, smell, touch and taste all feed information into the brain simultaneously and constantly. Under normal circumstances, a structure called the thalamus acts as a filter, prioritising which sensory information reaches conscious awareness.
When that filtering system becomes overwhelmed, the result is hyperarousal: an escalating sense of discomfort, irritability, anxiety and fatigue that can range from mildly unpleasant to genuinely debilitating. The brain’s prefrontal cortex goes into overdrive trying to process everything at once, and what you’re usually not aware of, such as background noise, the hum of a fan or the temperature of a room, suddenly becomes impossible to filter out.
It’s not the same as being overwhelmed
The distinction is worth making. Being overwhelmed is an internal experience, driven by the volume of thoughts, tasks, decisions or emotional material you’re carrying. Feeling overstimulated is an external experience, triggered by the sensory environment around you.
Both can co-occur, and they often do. Being in an already-stressed state lowers your threshold for sensory overload, which means that a situation that would be manageable on a calm day can tip you over the edge when you’re already carrying a lot.
Who is most affected?
Everyone has a threshold beyond which sensory input becomes overload, but that threshold varies significantly. People who are neurodivergent, including those with ADHD, autism spectrum conditions or sensory processing differences, tend to reach that threshold more easily and experience overstimulation more intensely.
Around 30 per cent of the general population scores high on what researchers call sensory processing sensitivity, sometimes described as being a highly sensitive person. This trait involves a more sensitive nervous system, a lower sensory threshold and a tendency to process environmental information more deeply. It’s not a disorder but a personality characteristic, and it explains why some people consistently need breaks from social environments that their peers find entirely comfortable.
How to manage it in the moment
The most immediate intervention is removing yourself from the stimulus or reducing its intensity. Stepping outside, moving to a quieter space or simply closing your eyes briefly gives the brain’s filtering system a chance to reset. Even a few minutes in a lower-stimulation environment can be enough.
Exhale-focused breathing, specifically the kind that emphasises a long, slow sigh after two shorter inhales, is one of the most effective physiological tools for reducing hyperarousal. Research consistently shows it lowers heart rate and subjective anxiety faster than most other breathing techniques. Caffeine amplifies overstimulation significantly, so if you know you’re heading into a high-stimulation environment, that extra cup may make things meaningfully worse.
Longer-term strategies
Building periods of low stimulation into your daily routine, particularly in the afternoon when overstimulation peaks according to research, reduces the cumulative load. Time in natural environments, even twenty minutes in a park or garden, has been shown to measurably reduce cortisol levels. Limiting social media in high-stimulation environments is another evidence-based recommendation, as short-form video content is particularly demanding on the brain’s processing capacity.
Physical touch from someone you trust, or even gentle self-soothing touch, such as placing a hand over the heart, activates the release of oxytocin and measurably reduces the stress response.
Knowing the difference helps
Understanding whether what you’re experiencing is overstimulation or overwhelm matters because the solutions are different. If the source is external, changing or leaving the environment is the most direct response. If the source is internal, practical support around workload, decisions, or emotional processing is more useful.
Most people who experience overstimulation regularly benefit from identifying the specific environments and conditions that trigger it, and planning accordingly, whether that means choosing quieter venues, building in recovery time after high-stimulation events, or simply giving themselves permission to leave when things get to be too much.
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Featured Image: Pexels
