Nepedia
Back to Discover
Advanced Reader
🧬

Earwax

life science Maturity 11-13 Next article →

Earwax, known medically as cerumen, is a waxy substance produced in the ear canals of humans and other mammals. It serves as a vital protective layer for the auditory system. Cerumen protects the delicate skin of the ear canal from drying out. It also acts as a shield against water, fungi, and various types of bacteria. Furthermore, it traps particulate matter, such as dust, before it can reach the eardrum.

Ear Wax
Ear Wax

The production of cerumen involves a complex biological mechanism. It is created in the cartilaginous outer third of the ear canal. Two types of glands work together to produce this substance. Sebaceous glands release sebum, which is an oily substance. Meanwhile, modified apocrine sweat glands secrete a less-viscous fluid. These secretions mix with hair and shed layers of skin to form the final wax. On average, about 60% of earwax consists of keratin, which comes from skin cells. The remaining parts include 12–20% long-chain fatty acids, alcohols, and squalene, plus 6–9% cholesterol.

There are two distinct types of earwax determined by human genetics. The first is the wet type, which is a dominant trait. This version is typically light brown or dark brown and has a viscous, sticky consistency. It contains about 50% lipid, or fats. The second is the dry type, which is a recessive trait. Dry earwax is usually gray or tan and feels brittle. It contains only about 20% lipid and has fewer pigment granules than the wet type.

Dry earwax cropped
Dry earwax cropped

These two types are caused by a single base change in the ABCC11 gene. This gene is known as the ATP-binding cassette C11 gene. People who are homozygous for adenine (AA) have the dry type. Those with at least one guanine (AG or GG) have the wet type. Genetic distribution varies significantly across the globe.

World map ABCC11 A Allele
World map ABCC11 A Allele

Africans and Europeans are more likely to have wet-type earwax. Conversely, many East Asians, Southeast Asians, and Native Americans are more likely to have the dry type. About 30–50% of South Asians, Central Asians, and Pacific Islanders also possess the dry type.

Cerumen provides a natural defense through antimicrobial effects. While older studies found little evidence of this, modern research shows cerumen has a bactericidal effect. This means it can kill certain strains of bacteria. It can reduce the viability of bacteria like Staphylococcus aureus and Escherichia coli by as much as 99%. This defense is due to the slight acidity of the wax, which has a pH around 6.1. The presence of saturated fatty acids and lysozyme also helps inhibit the growth of fungi.

The ear canal possesses a self-cleaning mechanism called epithelial migration. This process works like a conveyor belt. New cells form at the umbo, which is the center of the tympanic membrane. These cells move toward the walls of the ear canal and eventually toward the entrance. As these cells migrate, they carry cerumen and trapped debris outward. Jaw movement, such as chewing, assists this process by dislodging debris from the canal walls. This natural movement helps prevent the buildup of harmful materials.

Sometimes, the cleaning process is interrupted, leading to impacted cerumen. This occurs when excess wax builds up and creates a blockage. Impacted wax can cause ear pain, dizziness, itching, or conductive hearing loss. It can also cause tinnitus, which is a constant ringing in the ears. Hearing aids can sometimes contribute to this by blocking the natural exit of wax. In fact, earwax is responsible for 60–80% of all hearing aid faults. If wax is stuck, medical professionals use various methods to remove it safely.

Doctors use several professional techniques to treat impacted wax. One method is cerumenolysis, which involves using softeners like oil or urea hydrogen peroxide to loosen the wax. Another method is microsuction, which uses a vacuum probe and a camera to extract the material. Some practitioners use ear irrigation, or syringing, which uses warm water to wash the wax out. While ear picks or curettes are used in some cultures, they require great skill to avoid damaging the eardrum. Most experts advise against using cotton swabs, as they often push wax deeper into the canal.

693 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (4)
File:Ear Wax.JPG
Ear Wax.JPG
File:Dry earwax cropped.jpg
Dry earwax cropped.jpg
File:World_map_ABCC11_A_Allele.svg
World_map_ABCC11_A_Allele.svg
File:An ear-cleaner, attending to a man's ear. Gouache painting Wellcome L0022250.jpg
An ear-cleaner, attending to a man's ear....
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.