Olfactory Overload: Knowing the Neurodivergent Nose

Kim Crowder recounts, discusses, and explores neurodiversity and a heightened sensitivity to smell.

Olfactory: Of or pertaining to the sense of smell; concerned with smelling. The Shorter Oxford English Dictionary.

My first post-pandemic train journey. Apprehensive. Exhaling. Inhaling. Finding my way into the carriage’s smell-scape. Fragrances competing. Perfume? Fabric conditioner? Breathing deeper. Exploring the atmosphere. Whiff of stale bath-towel. Drifting taints of fishy crisps, garlic, fruity gum. Someone trailing a sillage of greasy dog. Across the aisle, a woman pouring soup from a flask. She sips and blows – diffusing stinking steam. Feeling the smell’s sledgehammer impact. Rank blue cheese and broccoli, synthetic chemical-based flavourings. The hex of hexanoic acid, redolent of vomit. Disgust. Must deflect this sensory onslaught. Exhaling. Wanting the stink out of my nostrils, my system, my mind: now. Resist. But the inhalation reflex can’t be over-ridden. Compelled to keep absorbing the stink, breath by breath. Four stations to go. Zipping my coat to my chin. Excluding the smell. Not wanting it to permeate clothes or hair. Concealing stress. Shutting down. Not daring to glare at the soup drinker. Anxious. Dreading the onset of olfactory overload.

* * * 

I am autistic and have hyperosmia, the heightened scent-sensitivity experienced by many neurodivergent people. The conditions bring positives and negatives. There’s delight in identifying the elusive undertones of aromas. Gorse blossom’s coconut perfume is tinged with hints of hay, rain, and meths; lilac conjures up sugar, butter, wet metal. I’m quick to detect taints of smoke, damp, rot. An ammoniac edge to my epileptic dog’s saliva predicts impending seizure.

For me olfaction works like proprioception, that is, the awareness of the position and movement of the body in space. Distinct as architectural forms, individual smells have their own size, extent, and contour, and olfaction helps me navigate, orientate myself. Smells tell me which places are tolerable, which are not. Swimming pools, burger bars, coffee shops, and hand-made soap shops are no-go zones. Ambient marketing smells, those insidious imposters masquerading as bread, wine or coffee, ambush me in shops. Environmental fragrancers – scented candles, air fresheners – are poison, not perfume, for me. Petro-chemical vapours send me into sickly spin.

I can be incapacitated by my olfactory capacities. ‘Wrong’ smells trigger scent-sickness – headache, nausea, trembling, anxiety, debilitation, sometimes meltdown and burn-out. The worst smells resemble contagions and, like viruses, they can be contracted. The remedy for the sickness that olfactory overload brings is seclusion, known in neurodiversity parlance as elopement: no socialisation, no work, no sensory stimuli, no food – nothing.

Nausicaa: “..a hogo you could hang your hat on” (detail). P.F.White.

Amongst my 25,000 daily breaths, some will produce scent-sickness symptoms. But how does the vital function of breathing catalyse such devitalising effects? The workings of the limbic system suggest some answers. Set deep in the forebrain, the limbic system includes the amygdala, hippocampus, hypothalamus – and the olfactory bulbs which recognise different smells and enhance smell detection (Herz, 2001; Olfactory bulb, 2023). Together, these organs influence the nexus of memory-formation, -retrieval, and -regulation. Emotion and sensory reactions, including the fight/flight response, are also involved. Of the five senses, olfaction alone is implicated in limbic brain functioning.

In medical terminology the term limbic, from the Latin limbus (border, edge), refers to an anatomical component’s border. But, to an anthropologist like me, the term is enticingly evocative of the liminal, an enduring theme explored by Van Gennep (1909) and Turner (1982). Liminal places include thresholds, in-between zones (physical, mental, or abstract). People may enter the state of liminality during rituals, rites of passage or transitions entailing a phase of being neither one thing nor the other, being betwixt and between – in limbo. Sandwiched between the cerebral hemispheres, the limbic system operates within a neither-nor realm of interpenetrating neurological borderlines where feelings, memories, behaviours, instinct, intellect, and the emotion-inflected sense of smell, all coincide.

During the soup incident, I experienced the transition between feeling fine and feeling ill. Another betwixt and between duality arose too, involving sensations and thoughts driven by my breathing. The hiatus between each inhalation and exhalation repeatedly left space for doubt: would the smell still be detectable at the next breath, or gone? Was it external or internal to my body? Was I remembering or experiencing it? Was I or wasn’t I succeeding in hiding my acute discomfort?

Lestrygonians: “…stink gripped his trembling breath” (detail). Peter F. White.

Compulsive repetition is familiar to many neurodivergent people, manifesting sometimes as physical movements (stimming), and sometimes as reiterated words. A catchy tune might lodge as an endlessly looping ‘ear-worm’, and, equivalently, a smell can act as a ‘nose-worm’, re-playing with the maddening insistence of snoring or a dripping tap. Where the neurotypical nose sniffs, moves on, and forgets, the neurodivergent nose and brain can’t let go. An unwelcome smell intensifies one breath at a time, invading nasal cavities, permeating the brain, the mind – triggering an olfactory echo-chamber effect lasting long after the smell’s disappearance. Like the respiration-linked pause I described, olfactory echoing produces a strange intellectual impression, an oscillation between my own powerfully felt sensations and my realisation that others are not feeling what I feel.    

Being caught in a dilemma also corresponds with liminality. While reacting negatively to a smell, a neurodivergent person may feel the opposing impulses of the flight/fight response. The neurodivergent tactic of masking (also known as camouflaging) has recently become better recognised, especially amongst women and girls (Attwood, 2007; Hendrickx, 2015; Egeskov, 2019). Adept at concealing powerful reactions and emotions, they mimic the normal behaviours of others so as to fit in socially. Masking can deflect negative attention and help to avoid making others feel uncomfortable, the latter directly contradicting assumptions that neurodivergent people can’t empathise.

So, on the train, I was caught between instinct and intellect: should I reveal or conceal my acute smell-induced discomfort? Tolerate or react? Instinct said “Escape!”, while intellect, etiquette and the masking impulse insisted “It’s not OK to complain about or run away from the smell of soup”. Why did this dilemma matter? Because being trapped in indecision undermined my masking ability. Failure to mask competently, or worse, being unmasked, risked my exposure as socially strange – vulnerable to negative attention.

Bad smells and dirt are correlates. Being dirtied by a polluting smell chimes with Douglas’s (2002:2,50) famous assertion that dirt, figured as ‘matter out of place’, equals disorder. To me, olfactory disorderliness occurs when domestic smells cross the boundary into public space. Food smells lingering on my clothes might elicit misperceptions of me as ‘dirty’. Drobnick (2006:15) pinpoints a prevalent idea, one that troubles me: good smells emanate from those who are virtuous or socially elevated, whereas bad smells come from the corrupt or low-ranking. Given that fastidiousness about cleanliness and order accompanies my autism, I resist being misidentified as a smelly, socially unacceptable other, especially if the smell concerned isn’t actually mine.  As much as I dread the onset of scent-sickness, I also fear such mis-recognition.

The current view of autism – which emphasises ‘difference not deficit’– is relevant here. While I value the distinctiveness that neurodivergence brings, certain unhappy pre-diagnosis and childhood memories still make me wary of attracting negative attention to my putative ‘deficiency’. The liminal appears once again in my awareness of occupying the gap between what I actually am and how I may be perceived. My double-edged feelings of perceptual sharpness mingled with psychological uncertainty prove Howes’s (1991) point that ‘Olfaction is the liminal sense par excellence’.

I don’t claim to speak for all neurodivergent people, as sensory traits occur in myriad combinations and intensities. However, discussions with my autistic contacts confirm that chance encounters with overpowering or out-of-place smells in public spaces are damaging to the wellbeing of many – a problem that deserves attention. The social sciences have already shown how olfaction contributes to numerous processes – identity formation, place-making, power relations, and more (Drobnick 2006:5-17). Medico-scientific studies (often focused on children or adult males) have tested and measured neurodivergent olfaction from the perspectives of ‘impairment’ or ‘condition’ (Ashwin et al. 2014). What is lacking is exploration and acknowledgement of the insights that neurodivergent people themselves can provide regarding their own lived experience of olfaction-induced difficulty.

A positive feature of recent literature on olfaction is the presence and richness of neologisms. As smells and smelling are notoriously difficult to capture linguistically, a vigorous and expanding vocabulary is a prerequisite for improved understanding and appreciation of all olfactory capacities, and neurodivergent ones in particular. Without the right words, and the relevant knowledges, how can olfaction’s problematic aspects be properly addressed – and, importantly, how can better social accommodations for neurodivergent peoples’ olfactory sensitivity be devised? How might the wellbeing and rights of scent-sensitive people be protected when corporate/capitalist interests are deliberatively coupled-up with profit-driven olfactory influencing? Given the increasing application of such olfactory manipulation tactics, the issue is pressing.

It is ironic that deodorisation (removing/concealing ‘bad’ smell) and odourisation (adding ‘good’ smell) can both produce troublesome olfactory reactions: the ‘good’ and the ‘bad’ are such highly subjective categories. This, coupled with the virtually uncontrollable invasiveness of smell, means that the problem of managing intrusive smell is a difficult one, but hopefully not completely insoluble. Ideally, all publicly accessible spaces, along with workplaces, might one day include smell-neutral areas offering refuge and respite from the effects of unwanted smells. Perhaps such change might begin on trains, their quiet coaches accompanied by smell-minimised ones, neither deodorised or odorised?

About the author

Kim Crowder holds a Ph.D in Visual Anthropology (Goldsmiths, 2012) and her writing has been published in literary magazines, anthropological collections and blogs. Kim is a member of the prescription medical humanities writing group led by Dr. Gillean McDougall at the Royal College of Physicians and Surgeons of Glasgow. This article was inspired by the group’s recent workshop exploring the topic of breath.

More writing available at www.livesinnature.co.uk  

Giliean McDougall’s most recent piece for The Polyphony can be found here.


Ashwin, C., Chapman, E., Howells, J., Rhydderch, D., Walker, I., Baron-Cohen, S. 2014. Enhanced olfactory sensitivity in autism spectrum conditions. Molecular Autism 5, 53. https://doi.org/10.1186/2040-2392-5-53 Accessed 20/5/2023.

Attwood, T. 2007. The Complete Guide to Asperger’s Syndrome, London and Philadelphia: Jessica Kingsley, p.46.

Douglas, M. 2002 [1966]. Purity and Danger: An analysis of the concept of pollution and taboo, London: Routledge.

Drobnick, J. (Ed.) 2006. The Smell Culture Reader. Berg; Oxford. New York.

Egeskov, C. 2019. The Art of Masking: Autistic Women who Mask. https://www.tiimoapp.com/blog/art-of-masking-women-with-autism/ Accessed 6/6/2023.

Hendrickx, S. 2015. Women and Girls with Autism Spectrum Disorder: Understanding life experiences from early childhood to old age, London and Philadelphia: Jessica Kingsley, pp. 22, 30, 31.

Herz, R. S. 2001. Ah, Sweet Skunk! Why We Like or Dislike What We Smell.  https://dana.org/article/ah-sweet-skunk-why-we-like-or-dislike-what-we-smell/ Accessed 6/6/2023.

Howes, D. 1991. Olfaction and Transition, in D. Howes (Ed.) The Varieties of Sensory Experience, Toronto: University of Toronto Press, pp. 128-47.

Olfactory bulb. https://en.wikipedia.org/wiki/Olfactory_bulb Accessed 6/6/2023.

Onions, C.T. (Ed.) 1973. The Shorter Oxford English Dictionary. Oxford: Clarendon Press.

Turner, V. 1982. From Ritual to Theatre. The Human Seriousness of Play, New York: Performing Arts Journal Publications.

Van Gennep, A. 1977 [1909]. The Rites of Passage, London: Routledge.

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