Surfer's ear
Also called: External auditory canal exostosis · Ear canal exostoses
Years of cold water and wind on the ear make small lumps of new bone grow inside the ear canal. About two in three surfers have some. Neanderthal skulls show it too, more often than those of early modern humans.
How common
Do you have this?
How it works
The inner part of the ear canal, near the eardrum, is a tunnel of bone. The skin over it is very thin, about 0.1 mm, with no fat to keep the bone warm1. Repeated cold water and wind make this bone grow. Over years, smooth lumps of new bone rise from the canal walls12.
The exact mechanism is not confirmed. The common idea is that cold irritates the thin layer that covers the bone, and the bone cells respond by laying down new bone1.
Time in cold water is the main risk. It forms more often in water colder than 19 °C (66 °F)1. In one study of 202 surfers, those who surfed mostly in cold water had 5.8 times the odds of having it. Each year of surfing raised the risk by about 12%4.
Swimmers, divers, kayakers and sailors get it too1. It is not swimmer’s ear, which is an infection of the ear canal2.
Studies of ear protection partly disagree. In a French study, time in earplugs was not linked to more growth, but time in a surf hood was6. An English study found that earplugs or a hood lowered the risk7.
How common it is
A 2024 review pooled 19 studies with 2,997 surfers in the USA, Europe, Australia, New Zealand and Japan. Rates ranged from 53% to 90%, with a mean of 67.8%3. One study of young US surfers, median age 17, found only 38%4.
No good figure exists for the general population. Men have it more often than women, probably because more men do cold-water sports1. It is usually found in adults aged about 20 to 5012.
Is it a problem?
Usually not. Most people with it have no symptoms1. The lumps are harmless but permanent1. A normal ear canal is about 7 mm wide. The lumps can trap water and ear wax. This can cause a blocked feeling, repeated ear infections and some hearing loss12. People often see a doctor when the gap is down to 0.5 to 2 mm2.
Mention it to a doctor if you have a blocked ear that does not clear, repeated ear infections, or hearing loss. A doctor can see the lumps with an ear light1.
History and culture
Bone lasts, so researchers use these lumps to tell which ancient groups spent a lot of time in water1. A 2019 study of 77 fossil ear canals found them in 56.5% of Neanderthals, or 47.8% if two unclear cases count as normal. Early modern humans had them in about 10% to 25%5. The authors think Neanderthals often gathered food in water, though other factors may have played a part5.
Sources and further material
- NCBI Surfer's Ear (StatPearls) Free medical reference chapter. Covers the cause, the proposed mechanism, who gets it, and the symptoms.
- Wikipedia Surfer's ear Gives the normal canal width of about 7 mm. Says it is not the same as swimmer's ear.
- PubMed External auditory exostosis among surfers: a comprehensive and systematic review 19 studies, 2,997 surfers. Rates from 53% to 90%, mean 67.8%.
- PubMed Surfer's ear: external auditory exostoses are more prevalent in cold water surfers 202 young surfers, 38% affected. Cold water gave 5.8 times the odds. Risk rose 12% per year of surfing.
- PubMed External auditory exostoses among western Eurasian late Middle and Late Pleistocene humans 77 fossil ear canals. Found in 56.5% of Neanderthals, and about 10% to 25% of early modern humans.
More sources for this oddity (2)
- PubMed Impact of ear protection on occurrence of exostosis in surfers: an observational prospective study of 242 ears Brittany, France. About 90% of ears affected. Time in earplugs was not linked to growth. Time in a hood was.
- PubMed The effects of surfing behaviour on the development of external auditory canal exostosis 207 surfers in south-west England, 53% affected. Earplugs or a hood lowered the risk.
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Related oddities
Torus palatinus
A hard bony lump along the midline of the roof of the mouth that grows slowly and is completely harmless. Many people find it by chance and worry that it is a tumour. A similar bump inside the lower jaw is a torus mandibularis.
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Diving reflex
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Cold diuresis
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Tinnitus
A ringing, hissing, buzzing, or roaring sound with no source outside your head. Between 10% and 15% of people have it. It is mostly the hearing system filling in for damaged or tired inner-ear cells.