Sensory overload: what's happening, and what helps (an Autistic guide)

What sensory overload is

Sensory overload occurs when the total sensory input in your environment goes beyond what your nervous system can process at that moment. It isn't a reaction to attention or a behavioural display. It's a physiological state, as real and involuntary as a migraine.

Sensory differences aren't a side feature of autism. They are central to it, and they shape attention, emotion, communication and energy all the time. That's why we use the word bodymind, a term from disability studies that refuses to split body and mind apart (Clare, 2017; Price, 2015): the noise in a room, the stress in your chest and the way you behave are one thing, which services carve up into separate pieces afterwards.

Why it builds up (and why “nothing happened” is rarely true)

Overload is additive. A fluorescent light might be fine by itself. So might a background hum, or the smell of a cleaning product. But all three together, in an already stressful situation with social demand added, can push you past your threshold, and the tipping point isn't visible from outside.

It's also carried forward. Your threshold today depends on what happened on previous days. If Monday was loud, you start Tuesday closer to the edge even if Tuesday looks ordinary. That's why a small trigger can produce a big reaction, and why “but nothing happened” is so rarely true. Something did happen. It happened last week, and your system never fully discharged it.

For monotropic minds, attention is often pulled strongly toward sensory input, which can make it harder to filter out (Murray et al., 2005). See our guide to monotropism and the Autistic Realms monotropism guide.

You have more than five senses

Most of us learn five senses. There are at least eight, and Autistic people can be over-responsive (hypersensitive), under-responsive (hyposensitive) or both, in any of them, depending on the day, your stress, your health and your hormones. Many Autistic people find sensory sensitivity intensifies around perimenopause and menopause (Moseley et al., 2020). See Autistic Realms' menopause resources.

• Sight, sound, smell, taste and touch: flicker from fluorescent lights, difficulty filtering one voice from background noise, strong scents, food textures and clothing tags. With sound the problem is often inability to select, not better hearing.
• Proprioception: your sense of where your body is and how hard you're pressing. Many people seek deep pressure and heavy, purposeful movement because it helps them feel grounded and organised.
• The vestibular sense: balance and movement. Some crave rocking or spinning, others find lifts and car journeys disorienting.
• Interoception: the sense of your body's internal state, like hunger, thirst, pain and the physical side of emotion. It is often different in Autistic people (Garfinkel et al., 2016), and it's why “I don't know how I feel” can be the exact truth. Kelly Mahler's interoception work is a good place to read more.
• If you're AuDHD, you might be both sensory-seeking and sensory-avoiding: craving movement and stimulation while finding noise unbearable. Both needs are real.

Early signs of overload

Getting to know your own early signs, and perhaps deciding in advance what might help, can make a real difference. Some common ones:

• More stimming
• Withdrawing from conversation
• Feeling more on edge or irritable
• Reduced or lost speech
• Trouble concentrating
• Needing more sameness, predictability or control
• A flattening of expression that can look like calm

What helps

Overload can't be fully prevented, and it isn't a failure when it happens. The goal isn't a life with none, which would need a level of control over your environment that isn't possible or desirable. The aim is for overload to be anticipated, met with less demand rather than more, and followed by recovery rather than consequences.

• You might look gently at your spaces: light, sound, smell, temperature, seating, visual clutter and how predictable the place is. Small changes at this level are often the most decisive.
• Sensory breaks often help most before you need them. Rest at crisis point is still important; rest built into your day can help prevent the crisis.
• Use sensory tools without apology: ear defenders, earplugs, sunglasses indoors, weighted or chewable items, fidgets. In the UK, sensory tools at work or study can be a reasonable adjustment under the Equality Act 2010.
• Let yourself stim and move. Movement is often the most effective regulator available.
• Where you can, try not to stack demands. Managing sensory challenge and social performance at the same time is a lot to ask of anyone.
• Track your week, not just your day. Look at what a Monday costs before judging a Thursday.
• For people with profound and multiple learning disabilities, or who don't use speech, overload is communicated through behaviour and the body. The people around them carry the responsibility to notice. See The Sensory Projects.

Common questions

Is sensory overload the same as anxiety?

They can overlap and feed each other, but overload is a response to total sensory input exceeding what your nervous system can currently process. It is physiological and additive, and often needs reduced stimulation and recovery, not reassurance.

What happens if sensory overload isn't relieved?

It can tip into a meltdown or a shutdown, both of which are responses to overwhelm. Over a longer time, sustained sensory load without recovery is one of the drivers of Autistic burnout (Raymaker et al., 2020).

Can you be over-sensitive and under-sensitive at the same time?

Yes. You can be hypersensitive to one sense and hyposensitive to another, or even both within a single sense, for example painfully sensitive to high pitches while struggling to pick out one voice in background noise.

Why do I feel worse after a busy day even when nothing bad happened?

Load is cumulative and carried forward. The total across the day, plus what you started with, is what counts, and small things add up without you noticing until you pass your threshold.

References

• Clare, E. (2017). Brilliant imperfection: Grappling with cure. Duke University Press.
• Garfinkel, S. N., Tiley, C., O'Keeffe, S., Harrison, N. A., Seth, A. K., & Critchley, H. D. (2016). Discrepancies between dimensions of interoception in autism: Implications for emotion and anxiety. Biological Psychology, 114, 117–126.
• Moseley, R. L., Druce, T., & Turner-Cobb, J. M. (2020). "When my autism broke": A qualitative study spotlighting autistic voices on menopause. Autism, 24(6), 1423–1437.
• Murray, D., Lesser, M., & Lawson, W. (2005). Attention, monotropism and the diagnostic criteria for autism. Autism, 9(2), 139–156.
• Price, M. (2015). The bodymind problem and the possibilities of pain. Hypatia, 30(1), 268–284.
• Raymaker, D. M., Teo, A. R., Steckler, N. A., Lentz, B., Scharer, M., Delos Santos, A., Kapp, S. K., Hunter, M., Joyce, A., & Nicolaidis, C. (2020). "Having all of your internal resources exhausted beyond measure and being left with no clean-up crew": Defining autistic burnout. Autism in Adulthood, 2(2), 132–143.