A fluorescent light hums. Someone nearby is chewing. The tag on your shirt keeps scratching your neck. None of these should be a crisis. But right now, each one feels unbearable.
That is sensory overload, and it is not a choice or an overreaction. It is your brain struggling to filter what matters from what does not.
A Filtering Problem
Your brain constantly sorts incoming signals and decides what deserves your attention. This process is called sensory gating. When it works well, you barely notice the hum of a refrigerator or the texture of your socks.
When gating falters, everything arrives at full volume. A brain imaging study at UCSF found that people with sensory processing differences have atypical white matter tracts, the wiring connecting sensory regions. These structural differences alter the timing of sensory signals, making it harder for the brain to integrate multiple inputs at once.
Neurochemistry plays a role too. Lower levels of GABA, a chemical that helps quiet neural activity, in sensory relay areas like the thalamus mean less braking power on incoming sensation.
Sensory overload is especially common in neurodivergent brains. Prevalence studies estimate that sensory processing difficulties affect roughly half of people with ADHD and over 80% of autistic individuals. But high stress, sleep deprivation, or burnout can push anyone past their threshold.
Working With It
You can not rewire sensory gating overnight, but you can work with it.
- Reduce the input. Close your eyes, cover your ears with your hands, or turn away from the brightest light source. Removing even one channel of stimulation can bring you back below your limit.
- Name the trigger. Identifying which sense is overwhelmed (sound, light, touch) helps your brain shift from reacting to processing.
- Recover without guilt. Needing quiet after a high-input environment is not weakness. Your nervous system needs time to reset. The fluorescent light will still hum. But when you understand why it hits so hard, you can make room for yourself instead of pushing through.
