Does Earwax Come Out by Itself, Even If You Never Clean Your Ears?
― The Skin in Your Ear Canal Is a Slow "Walkway" Heading Outward
If you skip ear cleaning, it feels as if earwax must keep piling up. In fact, the skin of the ear canal itself is slowly moving from deep inside toward the opening. Earwax rides on top of it and is carried out.
After a bath, cleaning your ears with a cotton swab feels satisfying. But what comes out is always earwax from near the opening.
Your eardrum sits about 2 to 3 centimetres inside from the entrance. If earwax were being made deep in there all the time, it would seem bound to block the eardrum eventually.
Yet even people who rarely clean their ears don't usually lose their hearing. So where does the earwax go?
Earwax leaves on its own for two reasons
The skin of the ear canal is thought to move from the centre of the eardrum toward the opening at about 0.05 mm a day. Anything sitting on it is slowly carried out.
The tiny glands that produce the fluid behind earwax are found only in the outer third of the canal. The skin deeper in is thin and makes no earwax.
In other words, earwax is born "right next to the exit" and leaves on an outward-moving walkway. Let's look at each in turn.
The skin of the ear canal works like a "moving walkway"
Normally, the skin on the surface of the body flakes off as dead skin when it gets old. But the ear canal is a narrow dead-end tube, so flaked skin has nowhere to fall.
So the skin of the ear canal does something different. New skin is made around the centre of the eardrum. From there, the surface of the skin is gradually pushed outward.
This was confirmed in experiments where a small ink mark was placed on the eardrum and followed for several weeks. The mark travelled toward the edge of the eardrum, then along the wall of the ear canal toward the opening.
Look at Figure 1. The right end is the eardrum and the left end is the ear's entrance. Move the slider to change the number of days and watch the mark on the eardrum travel to the left.
Earwax is born next to the exit
The ear canal is built differently in its outer third and its inner two thirds. The outer part is made of cartilage, with thick skin and hairs. Here sit the glands that release oil and the glands that make the fluid behind earwax.
The inner two thirds is made of bone. The skin is very thin and has no glands. So earwax is made only near the entrance.
Earwax is a mixture of this fluid, flakes of shed skin and dust. From where it is made to the exit is less than a centimetre. Add the skin "walkway" and it usually works its way out even if you leave it alone.
Jaw movement from talking and chewing is also thought to help. The outer part of the ear canal lies right next to the jaw joint.
Cleaning with a cotton swab can actually cause blockages
A cotton swab can remove earwax from the outer part, but it also pushes some of it deeper. The skin deep inside is thin and has no glands, so it has very little power to carry pushed-in wax back out.
Wax that has been pushed in can pack together in front of the eardrum and form a plug. Then you may notice muffled hearing or a feeling of blockage. A clinical guideline from a US association of ear, nose and throat doctors also explains that the ear has its own way of cleaning itself.
If you do clean, gently wiping the part you can see from the entrance is considered enough. If the blocked feeling persists, it is safer to have an ear doctor remove the wax than to poke around deep inside yourself.
Earwax comes in a flaky, dry type and a sticky, wet type. In 2006, a Japanese research group showed that which type you have is decided by a difference in just one spot in a single gene. The dry type is common in East Asia, including Japan, and the wet type is common in Europe and Africa.
Summary
The skin of the ear canal moves slowly from the centre of the eardrum toward the opening. Earwax is made near the entrance and rides this movement out. If you push a swab in deep, you push the earwax back against this flow.
Your ears clean themselves.
All a person needs to handle is the area around the exit.
For how air behaves deep in the ear, see "Why do our ears hurt before a plane lands?" For how the inner ear keeps your balance, see "Why do we still feel dizzy after we stop spinning?"
- In front of a mirror, open and close your mouth wide while lightly resting a fingertip at the entrance of your ear canal. You can feel the entrance move with your jaw.
- Hold off on cleaning your ears for about two weeks, then gently wipe around the entrance with a tissue. Even without a swab, you may find earwax has come out near the opening.
- Ask your family whether their earwax is the dry or wet type. You may notice that parents and children tend to match.
* Do not put fingers or objects deep into your ear. If pain, itching or hearing trouble continues, see an ear doctor.
For those who want more ― terms, formulas and links to textbooksEach part is labelled by level, from middle-school science to university courses
- Middle schoolCovered in middle-school science
- High schoolCovered in high-school biology
- High school+Advanced high-school material, or content shown in textbook sidebars
- UniversityUniversity-level topics not taught in high school (histology, otolaryngology, human genetics)
- ResearchNot yet settled textbook knowledge, but being studied by researchers now
Middle schoolTerms: this phenomenon has names
- External auditory canal: the tube from the ear's entrance to the eardrum. In adults it is said to be about 2.5 cm long.
- Cerumen: the formal name for earwax. It is a mixture of fluid from glands, shed skin and dust.
- Epithelial migration: the surface layer of skin gradually moving in a set direction. In the ear canal, this is the self-cleaning mechanism.
Middle schoolHigh schoolChecking with a formula: how many days until the mark comes out?
If you know how fast the skin moves, you can estimate the days until the mark reaches the entrance as "distance ÷ speed". The speed varies with the measurement method and the person; here we use 0.05 mm a day as a reported rule of thumb.
| In symbols | t ＝ L ÷ v |
| In words | Days to come out ＝ distance to travel ÷ distance moved per day |
| Where it comes from | "Distance ＝ speed × time" for something moving at constant speed, rearranged for time |
| Symbol | Meaning and unit |
| t | Days to come out (days) |
| L | Distance to travel (mm) |
| v | Distance the skin moves per day (mm/day) |
| Length of the ear canal (eardrum to entrance) | About 25 mm |
| Length of the wax-making part (outer third) | About 8 mm |
| Distance the skin moves per day | About 0.05 mm (varies) |
| Length a fingernail grows per day | About 0.1 mm |
| Until the eardrum mark reaches the entrance | 25 ÷ 0.05 ＝ 500 days |
| In years | 500 ÷ 365 ≒ 1.4 years |
| Until wax made at the innermost point comes out | 8 ÷ 0.05 ＝ 160 days |
| In months | 160 ÷ 30 ≒ 5.3 months |
| Compared with nail growth speed | 0.1 ÷ 0.05 ＝ 2 times |
By this calculation, skin from the eardrum takes over a year to come out, while earwax reaches the exit in a few months at most. The skin walkway moves very slowly, at about half the speed a nail grows. Because it never stops, though, earwax does not keep piling up.
High schoolHigh school+How does skin "move"?
High schoolThe surface of skin is made of many stacked layers of cells. Cells divide in the bottom layer, and older cells are pushed upward until they become a thin layer of dead cells. In many parts of the body, this layer flakes off as dead skin.
High school+In the ear canal, this dead surface layer is thought to slide sideways instead of flaking off. The centre where new cells are born is said to lie near the middle of the eardrum. From there the layer spreads outward, passes from the edge of the eardrum onto the canal wall, and heads for the entrance.
UniversityEpithelial migration, and the gene that decides wax type
This phenomenon is called epithelial migration of the ear canal, and the canal's skin is a keratinized stratified squamous epithelium. The fluid behind earwax comes from the ceruminous glands, a kind of apocrine gland, the same family as the glands involved in underarm odour. The difference between dry and wet earwax has been reported to be decided by a single-base difference (a single nucleotide polymorphism) in the ABCC11 gene. This gene is also said to be linked to how strong underarm odour is.
📖 Derivations and further reading: Wikipedia, "Earwax" (Japanese edition) ／ Wikipedia, "External auditory canal" (Japanese edition)
ResearchWhat is still not clear
- What decides the direction. Why skin moves in only one direction, and how cells line up their orientation, is still not well understood.
- Differences in speed between people. Measured speeds differ quite a lot by person, age and location in the ear. Slower migration is suspected as one reason older people get blocked ears more easily.
- Earwax's protective power. Earwax is said to make it hard for bacteria and mould to grow, but studies disagree on how strong this effect is.
So the content of this article is also "an explanation based on what is known today." In particular, 0.05 mm a day is a rough guide, and the actual number of days varies widely.
Links to textbooks (by level)
| Level | Subject / unit | Where in this article |
|---|---|---|
| Middle school | Science, Year 2: "Stimulus and response (structure of the ear)" | Position of the ear canal and eardrum |
| High school | Biology: "Cell division", "Animal tissues" | Skin layers and old cells being pushed up |
| High school+ | Biology: "Genes and traits" (advanced) | The gene that decides earwax type |
| University | Histology, otolaryngology, human genetics | Epithelial migration, ceruminous glands, ABCC11 gene |
| Research | Studies of epithelial polarity and movement | What sets the direction and speed of movement |
| ― | Link to daily life | Why cleaning only the entrance is enough |
- Alberti, P. W. (1964) Epithelial migration on the tympanic membrane. Journal of Laryngology and Otology 78.
- Schwartz, S. R. et al. (2017) Clinical Practice Guideline (Update): Earwax (Cerumen Impaction). Otolaryngology–Head and Neck Surgery
- Yoshiura, K. et al. (2006) A SNP in the ABCC11 gene is the determinant of human earwax type. Nature Genetics
- Wikipedia, Japanese edition, "Earwax"
* This article is a science explainer for general readers. The figures given are rough guides meant to help you understand the mechanism. If ear pain, hearing trouble or a blocked feeling continues, do not treat it yourself; see an ear, nose and throat doctor.