Smell Sensitivity: The Underrated Overload

Most conversations about sensory overload start with noise, then light, then maybe scratchy clothes. Smell sensitivity tends to come last, if it comes up at all — which is odd, because for a lot of neurodivergent people it's one of the fastest routes to a wrecked afternoon. Smell Sensitivity: The Underrated Overload is the one that gets the least sympathy, because nobody can see it, you can't politely point at it, and "the bins smell weird to me" sounds like a complaint rather than a genuine load on your nervous system.

I'm Matt. I run Neuro Supply Co, and I'm one of the people who can clock a reed diffuser from the hallway and spend the next hour quietly furious about it without knowing why. This is the guide I wish someone had handed me years ago — practical, honest, and free of "have you tried a scented candle" energy.

Why smell hits so hard (and so fast)

Here's the bit that explains a lot. Smell is the one sense that skips the usual queue. Most sensory information passes through a relay station in the brain before it reaches the regions that handle emotion and memory. Smell, broadly, doesn't — it has a more direct line. That's why a single whiff of a school corridor or a hospital can drop you straight into a feeling before you've consciously identified the smell at all.

For a brain that already processes sensory input more intensely — which is common across ADHD, autism and related profiles — that direct line means a strong scent can land as a full-body reaction rather than a passing "ooh, what's that". You're not being dramatic. You're getting a louder signal, faster, with the emotional volume already turned up.

The other underrated factor is that smell doesn't switch off. You can look away from a light or take headphones off, but you keep breathing. A persistent smell — an air freshener, a colleague's aftershave, a damp coat — keeps arriving every few seconds, and there's no eyelid for your nose.

Noise has ear defenders and a vocabulary. Smell has a polite society that pretends it isn't happening — which is exactly why it sneaks up on you.

What smell overload actually feels like

It rarely announces itself as "I am bothered by a smell". More often it shows up sideways, and you only connect the dots later:

• A sudden drop in mood or patience with no obvious cause
• Feeling faintly nauseous, headachey or "thick-headed" in a particular room
• An urge to leave that you can't justify, so you stay and get more frazzled
• Difficulty concentrating that lifts the moment you step outside
• Genuine revulsion or even a gag reflex at something others find pleasant

Two things make it worse. The first is that pleasant-to-most smells — perfume, scented candles, fabric softener, "fresh linen" plug-ins — are often the worst offenders, so naming the problem feels rude. The second is that smell overload stacks with everything else. On a calm day a strong scent is annoying; on a day that's already loud and bright, it can be the thing that tips you from coping into shutdown. If you're not sure whether what you're feeling is sensory or something else, our guide on sensory overload versus anxiety is a useful sorting tool.

Spotting your own triggers

Smell triggers are weirdly specific and personal. Some people are fine with food smells and floored by synthetic fragrance; others are the reverse. The aim isn't to map every molecule — it's to notice patterns so you stop being ambushed.

For a week or two, jot a quick note whenever your mood or focus dips: where you were, what you could smell, how strong it was. You're looking for repeat offenders. Common ones include:

• Synthetic fragrance — plug-ins, scented candles, reed diffusers, "air fresheners", strong cleaning products
• Personal scent — perfume, aftershave, heavily fragranced laundry, hand cream
• Food and cooking — reheated lunches, fried food, coffee, fish
• Bodies and rooms — sweat, damp, smoke, bins, new carpet or paint

The point of a list isn't to declare war on the world. It's that "the meeting room with the plug-in" is something you can plan around, whereas "I just feel awful in there sometimes" is not. A simple brain-dump sheet — the kind in our free ND Starter Kit — is enough to start catching the pattern.

Practical ways to turn the volume down

You can't carry an off-switch for other people's noses, but you can stack small advantages until the load is manageable.

Control the air you can. At home and at your own desk, you have more power than you think. Skip the plug-ins and scented candles entirely. Choose fragrance-free cleaning products, unscented laundry detergent and unfragranced toiletries where you can — going low-scent in your own space lowers your baseline, so the unavoidable smells out in the world have less to stack on top of. A small fan or an open window moving air past you breaks up a stagnant smell far better than masking it.

Give yourself a clean breath. This sounds daft until you try it. A familiar, tolerable scent you actually like — a particular lip balm, a cotton hanky with a drop of an oil you choose, even your own jumper — can act as an anchor. Holding a known smell to your nose for a few breaths interrupts an intrusive one and gives your nervous system something neutral to land on. Some people find a menthol-type balm under the nose genuinely helpful in unavoidable situations like public transport.

Have an exit and use it. Five minutes of fresh air resets far more than pushing through. Treat "stepping outside" as maintenance, not failure. Reframing recovery as routine — not collapse — is the whole idea behind a sensory diet for adults: small, planned resets that stop the load building to breaking point.

Plan around the known traps. If a particular shop, room or commute is reliably bad, that's information. Shift the timing, pick a different route, ask to move desks, or pair the unavoidable bits with your own anchor scent and an exit plan. If smell is just one layer of a bigger pile-up, the broader kit on our sensory overload tools page covers the other senses too.

Asking for changes without the awkward conversation

The social side is genuinely the hardest part, because the trigger is often someone's perfume or lunch, and "you smell" is a sentence with no good delivery. A few framings that tend to land better:

• Make it about you, not them: "Strong scents give me headaches, so I keep my space fragrance-free — nothing personal."
• Ask for the environment, not the person: request that shared areas go low-scent, or that plug-ins aren't used in a small meeting room.
• Offer the alternative: "Could we crack a window?" is easier to grant than "could you not".
• In writing, frame it as an access need. Many UK workplaces will treat a fragrance-free or well-ventilated request as a reasonable adjustment if you raise it calmly.

You won't win every one, and that's fine. The goal is to remove the avoidable triggers so your energy goes to the ones you can't. If scent-related conflict at work is a recurring theme, the same calm-request approach in our piece on noise sensitivity at work maps almost exactly onto smell.

A note on diagnosis and when to see a GP

A heightened sense of smell, or strong reactions to scents, is a recognised part of many sensory profiles and is usually about how your brain processes input — not a sign something is medically wrong. This guide is practical support, not medical advice.

That said, see your GP if smell changes are sudden or new, if you're getting frequent headaches, breathing problems or nausea you can't explain, if a smell that isn't there keeps appearing (phantom smells), or if any of this is significantly affecting your eating, work or wellbeing. A doctor can rule out the handful of medical causes worth ruling out, and that's genuinely worth doing. For questions about diagnosis or medication, a GP is the right door — this page is here for the day-to-day.

Smell sensitivity isn't fussiness and it isn't in your head — it's real load on a system that's already working hard. Name it, map your own triggers, lower your baseline where you can, and keep an anchor and an exit in your pocket. That's most of the battle, and it's a battle you're allowed to take seriously.