Sensory Overwhelm: What It Is and What Causes It

Written By Kylie Brewer

Sensory overwhelm is a common and often intense experience within the neurodivergent community. For individuals with ADHD, autism, or both, the world can sometimes feel too loud, too bright, too busy, or simply too much. Sensory processing differences can make everyday environments exhausting or even painful, especially when multiple stimuli compete for attention at the same time.

What Is Sensory Overwhelm?

Sensory overwhelm occurs when the brain receives more sensory input than it can effectively process. This input can come from lights, sounds, textures, smells, temperatures, or even internal sensations. Common sensitivities include:

  • Bright or fluorescent lighting

  • Loud or unpredictable sounds

  • Certain textures in clothing or furniture

  • Crowded or visually busy environments

When sensory input becomes overwhelming, it can trigger a sensory meltdown. During a meltdown, it may feel like you are completely out of control—your nervous system goes into survival mode, anxiety surges, and your body may react with panic, shutdown, or emotional distress. This is not a choice or a failure; it is a neurological response.

Why Sensory Overwhelm Is Common in Neurodivergent Individuals

Neurodivergent brains are wired differently from those of the neurotypical majority. These differences affect how sensory information is filtered, interpreted, and regulated.

Some key neurological differences that may contribute to sensory overwhelm include:

  • Prefrontal Cortex (PFC):
    Research has found significantly more neurons in certain areas of the PFC—such as the dorsolateral PFC—in autistic children, with some studies suggesting up to 79% higher neuron counts compared to neurotypical children. While this may support advanced processing in some areas, it can also contribute to sensory overload and difficulty regulating attention or emotional responses.

  • Amygdala:
    The amygdala, which plays a major role in emotional processing and threat detection, may also differ. Young children with autism may have around 11% more neurons in the amygdala. Over time, this can reverse, with autistic adults showing fewer neurons, possibly due to chronic stress or overactivation. This can heighten anxiety responses during sensory overload.

  • Synaptic Density:
    Studies have shown that autistic adults may have lower synaptic density, with approximately 17% fewer synapses across the brain. Fewer connections between neurons can affect how efficiently sensory information is processed and regulated, making it harder to filter out unnecessary stimuli.

These neurological differences help explain why sensory overwhelm is not “overreacting,” but rather a genuine physiological experience.

Ways to Reduce and Manage Sensory Overwhelm

While sensory overload cannot always be avoided, there are strategies that can help limit its intensity and support nervous system regulation:

  • Use noise-canceling headphones or earplugs

  • Wear sunglasses indoors or outdoors to reduce light sensitivity

  • Limit time spent under fluorescent lighting when possible

  • Take 5–10 minutes to sit in a dark or dimly lit room

  • Use a weighted blanket for grounding and deep pressure input

  • Step outside or into a quieter space when overstimulated

  • Build regular sensory breaks into your day

Learning your personal sensory triggers and supports is a powerful form of self-advocacy.

A Final Thought

Sensory overwhelm is a valid and deeply real experience for many neurodivergent individuals. It is rooted in neurological differences—not weakness, not failure, and not something to “push through.” Creating sensory-friendly environments and honoring your body’s needs can make a meaningful difference in mental health, emotional regulation, and overall well-being.

You deserve comfort, understanding, and accommodations that allow you to thrive. 💛

Kylie Brewer