Swimmer's ear: what prevents it and what is folklore

Swimmer's ear is the injury that gets adult swimmers out of the water more often than any shoulder. It is not dramatic. You finish a session, the ear feels blocked, you assume the water will drain overnight, and by the following evening tugging your earlobe hurts enough that you cancel the morning swim.

Search for what to do about it and you will find a genre: garlic oil, hydrogen peroxide, a hairdryer at full blast, ear candles, a rubbing-alcohol recipe delivered with the confidence of a chemistry paper. Almost none of it has been tested. It is worth knowing which advice comes from a clinical guideline, which comes from a plausible mechanism nobody has trialled, and which is folklore repeated until it sounded official.

What swimmer's ear actually is

Swimmer's ear is an infection of the ear canal — the tube between the outside world and the eardrum. Its clinical name is acute otitis externa. It is a different condition from the middle ear infection that children get with colds, which sits on the far side of the eardrum and is not caused by swimming at all.

The distinction matters because the two feel different and are treated differently. The sign clinicians use is mechanical: in otitis externa, moving the outer ear hurts. Pressing the small flap in front of the canal, or pulling the earlobe down and back, produces pain out of proportion to how the ear looks. A middle ear infection does not do that. If you can tug your ear without flinching, whatever you have is probably not swimmer's ear.

Why water causes it, when your ear meets water every day

The ear canal defends itself with three things at once, and standing water removes all three.

Earwax is not dirt. It is a water-repelling, slightly acidic coating that keeps the canal skin dry and holds it at a pH hostile to the bacteria that cause the infection. Water that sits in the canal dilutes that acidity, raises the pH, and softens skin that is meant to stay intact. What is left is a warm, damp, neutral tube — which is close to a description of how you would culture Pseudomonas aeruginosa on purpose. That organism and Staphylococcus aureus cause most cases.

So the mechanism is not "water is dirty". It is water that stays. A minute of water in your ear is not the problem; forty minutes of a damp canal after every one of six weekly sessions is. Everything defensible about prevention follows from that single sentence, and everything that contradicts it — scrubbing the wax out, for instance — is working against you.

How common it is, and when

The American Academy of Otolaryngology puts the annual figure at roughly one person in every 123 in the United States. The Centers for Disease Control and Prevention counted about 2.1 million clinic visits for it in 2007, with a combined clinic and emergency-department rate of 8.1 visits per 1,000 people, and direct healthcare payments of around 489 million dollars a year. Around one person in ten will get it at some point in their life.

Two things stand out in those numbers. The peak is in children, not in adults, which is why so much of the advice online is written for parents of eight-year-olds and reads oddly if you are a masters swimmer. And 44% of visits land in June, July and August — the infection tracks swimming season and warm, humid air, not hygiene.

The uncomfortable part: the prevention advice has barely been tested

Here is the sentence that reorganises this whole topic. In its 2023 evidence review of acute otitis externa, American Family Physician notes that for the standard preventive measures — acetic acid drops, drying the canal — no randomised trials have been conducted to evaluate their effectiveness. These are sensible, near-universally recommended, mechanistically reasonable measures. They are not proven ones.

That does not make them worthless. Drying your ears costs nothing and cannot hurt you, so the absence of a trial is not an argument against doing it. But it does mean you should be sceptical of any page that tells you a particular routine prevents swimmer's ear, and more sceptical still of anything being sold to you on that basis. The honest framing is: these steps follow from the mechanism, they are low-risk, and nobody has demonstrated the size of the benefit.

What to do after every swim

All of this comes straight from the CDC's prevention guidance, and all of it is about getting water out rather than putting anything in.

• Tilt your head to each side so the ear faces the floor, and let it drain. Give it longer than feels necessary.
• Pull the earlobe in different directions while the ear is facing down. This straightens the canal and breaks the surface tension holding the water in place.
• Dry the outer ear with a towel. The outside, not the inside.
• If water still will not shift, a hairdryer on its lowest heat and lowest speed, held several inches away, is the CDC's own suggestion. Several inches, lowest setting — canal skin burns easily and you cannot feel it going wrong.

Two practical additions for people who swim often. Do the drainage routine on the poolside before you shower, not after, because the shower simply refills the canal. The shower still earns its place afterwards, for skin and hair. And if you swim doubles, the gap between sessions is the only time your canal has to dry out — worth knowing what that gap actually is, which is where the pace calculator is more useful than it looks: work out how long your main set genuinely takes and most sessions turn out shorter than they feel, and the recovery window longer.

What not to put in your ear

This is the half of the topic where the internet does real damage.

Cotton buds are the classic way to turn a damp ear into an infected one. The CDC's advice is to put nothing in the canal at all — not swabs, not a fingertip, not a corner of a towel. Two things go wrong at once: you scrape the skin barrier that is meant to be keeping bacteria out, and you push wax deeper, where it traps water instead of repelling it. Canal instrumentation is listed as a risk factor for the infection in its own right.

Do not try to remove your earwax before a swim, for the reasons above: the wax is the waterproofing. If you genuinely have a wax blockage affecting your hearing, that is a job for a clinician, not for a kit.

Ear candling does not work and can burn you. The US Food and Drug Administration classes ear candles as devices whose labelling is false and misleading, on the grounds that no validated evidence supports what they claim to do, and considers them dangerous when used as directed, given that the procedure involves a lit candle next to your face. They sit under an import alert. There is no version of this that belongs in a swimmer's routine.

Drying drops: who they are for, and who must not use them

The over-the-counter drying drops sold for swimmers are usually isopropyl alcohol with a little acetic or boric acid: the alcohol evaporates residual water, the acid pushes the canal back towards the acidity it is supposed to have. The mechanism is coherent. The trial evidence, as above, does not exist.

The important part is who should not use them. The CDC says to avoid ear-drying drops if you have ear tubes, a perforated eardrum, an active ear infection, or any discharge from the ear. This is not a mild caution. Alcohol and acidifying agents reaching the middle ear through a hole in the eardrum can do harm, which is why the clinical guideline for treating the infection has a whole recommendation devoted to using non-ototoxic preparations when the eardrum is not intact. If you do not know whether your eardrum is intact, that is the question to ask before you buy anything.

Earplugs and caps: what the evidence shows, which is less than you would hope

Earplugs, a swim cap pulled over the ears, or custom-moulded swim plugs are all on the CDC's prevention list, and they are the obvious answer to a problem caused by water entering a canal. But the closest thing to hard evidence points at a smaller effect than the recommendation implies.

A 2016 Cochrane review by Moualed and colleagues looked at water precautions in children with ventilation tubes — a related but not identical question. It found some evidence that wearing earplugs when swimming or bathing reduced the rate of ear discharge, but that the absolute reduction was very small and unlikely to be clinically significant, and noted that consensus guidelines advise against routine water precautions on the grounds that the limited benefit is outweighed by cost, inconvenience and anxiety.

Read that carefully, because it concerns a different population and a different question, and it is not a reason to throw your earplugs away. What it does argue against is the idea that plugs are the decisive intervention. In practice, for a swimmer with a history of the infection, plugs are cheap and harmless enough to be worth trying; for everyone else they are a preference, not a prescription. If plugs make you swim with your head high or wrestle with your goggle straps, the trade is a bad one — the same logic that applies to fixing goggles that fog rather than tolerating a bad seal.

Water stuck in your ear, or an infection starting?

Most blocked-ear feelings after swimming are water, and water leaves. What makes the distinction worth drawing is that the two need opposite responses: one needs patience, the other needs a clinician.

The itch is the underrated early sign. Itching in the canal a few hours after a swim, before any pain, is the point at which not scratching it — and not investigating it with a cotton bud — makes the most difference.

When it stops being an article's problem

The NHS says most ear infections clear within three days, though symptoms can last up to a week, and advises seeing a GP or pharmacist if things have not improved after three days or if infections keep coming back. It also advises against swimming while you have one. The AAO-HNS guideline tells clinicians to reassess at 48 to 72 hours if the patient is not improving, which gives you the same timescale from the other side.

Seek same-day medical care rather than waiting if you have swelling spreading around or behind the ear, fever, dizziness, a sudden change in hearing, or severe pain. The reason for that shorter fuse is a rare complication called necrotizing otitis externa, in which the infection extends into the surrounding bone. It overwhelmingly affects people with diabetes, older adults and people who are immunocompromised, and it is a medical emergency. If you are in one of those groups, do not run the three-day clock at home — the guideline itself treats diabetes and immunocompromise as factors that change the management from the outset.

What good treatment looks like, so you recognise it

You are not going to treat this yourself, but knowing the shape of standard care helps you ask the right questions.

Topical drops are the first-line treatment for uncomplicated cases, and the guideline specifically advises against oral antibiotics as initial therapy unless the infection has spread beyond the canal or there are host factors such as diabetes or immunocompromise. Most people improve within 24 to 72 hours of starting treatment, and between 65% and 90% have resolved within 7 to 10 days. Pain relief is part of the plan rather than an afterthought: the guideline has a key recommendation devoted to assessing pain and treating it.

Two other useful details. If the canal is swollen shut, drops cannot reach the infection and a clinician may place a wick — so "the drops are not working" sometimes means "the drops are not arriving". And a 2010 Cochrane review of treatments found acetic acid comparable to antibiotic-steroid drops in the first week, but less effective when treatment needed to run longer, with symptoms lasting about two days longer. Useful context if someone suggests vinegar drops for something that has already been going on for a fortnight.

The training side nobody writes about

If you get this repeatedly, the variable worth looking at is not your ears but your week. The infection is a function of cumulative damp-canal hours, and those go up when volume goes up, when sessions get longer, and when you add a second swim on the same day without a real gap between them.

That reframes it as a load problem, which is a problem swimmers already know how to solve. If your weekly distance has crept up, the question is whether the extra distance is doing anything. Knowing your critical swim speed and running your sets off it with the CSS calculator usually replaces a slab of aimless middle-pace metres with less time in the water for more training effect — which is also less time with a wet canal. It is the same argument as the one about swimming every day: frequency is only free if your tissues, ears included, get a recovery window.

And if you are preparing for an open-water event, note that the same canal gets colder, longer exposure in a lake than in a pool. Build that into the plan rather than discovering it during your first open-water swim.

Adults, children and the same infection

The peak incidence is in children aged 5 to 9, and the practical differences are worth stating. A child will not tell you their ear itches; they will get out of the water early, or become reluctant to put their head under. The drying routine has to be done for them, on the poolside, every time. And the temptation to "clean" a small child's ears with a cotton bud is exactly the thing to resist.

For adults, the pattern that recurs is a swimmer who has increased volume, trains in warm indoor air, and has a history of eczema or dry canal skin, which removes the same barrier that water does. If that is you, mention the skin history to your clinician: it changes the picture, and it is the sort of detail people leave out because it does not feel related.

What to do this week

Add ninety seconds to the end of every session: head to each side, earlobe pulled in a few directions, ear facing down, towel on the outside only. Do it before the shower. Put the cotton buds somewhere you will not reach for them. If you have had this more than once in a season, ask a clinician whether drying drops are appropriate for your ears specifically — that question, with your eardrum history attached, is the only version of this advice that is actually tailored to you.

Then go back to the part you can control, which is the swimming itself. The rest of the technique section covers what to do with the time you spend in the water, and an ear you have looked after is an ear that lets you keep spending it.