Earwax
Earwax protects, cleans, and lubricates the ear canal.
Earwax, which doctors call cerumen, is a waxy substance made inside the ear canal of people and other mammals. It can appear in shades of brown, orange, red, yellowish, or gray. Its job is to shield the ear canal’s skin, help keep the ear clean and lubricated, and defend against bacteria, fungi, dust, and water. The main ingredients are cerumen (produced by a type of modified sweat gland) and sebum (an oily substance), both made by glands in the outer ear canal. Chemically, earwax contains saturated and unsaturated long-chain fatty acids, alcohols, squalene, cholesterol, along with dead skin cells and hair.
Cerumen is made in the outer third of the ear canal, which is cartilaginous. It’s a blend of secretions from sebaceous glands and thinner fluids from modified apocrine sweat glands. Both wet and dry types of earwax are mostly shed skin layers—on average, about 60% is keratin, 12–20% is fatty acids, alcohols, and squalene, and 6–9% is cholesterol.
There are two genetically determined types: wet (dominant) and dry (recessive). This difference comes from a single base change in the "ATP-binding cassette C11 gene." People with dry earwax have two copies of adenine (AA), while those with wet earwax have at least one guanine (AG or GG). Dry earwax is gray or tan and brittle, with about 20% lipid content—less lipid and fewer pigment granules than wet earwax. Wet earwax is light or dark brown, sticky and viscous, with about 50% lipid. Wet-type earwax is linked to armpit odor, which increases with sweat. Some East Asians (including Yamato Japanese), Southeast Asians, and Native Americans (including Inuit) tend to have dry earwax, while Africans, Europeans, and other East Asians (including Ainu) more often have wet earwax. Among South Asians, Central Asians, and Pacific Islanders, 30–50% have the dry type.
Cleaning happens through a "conveyor belt" process of epithelial migration, helped by jaw movement. Cells from the center of the eardrum move to the ear canal walls and then toward the opening. This carries earwax outward, along with any trapped particles. Jaw movement also helps loosen debris from the canal walls. Removing earwax is a task for nurses, audiologists, family medicine doctors, and ear, nose, and throat specialists.
Lubrication from cerumen keeps the ear canal skin from drying out. The high lipid content in sebum—especially in wet-type earwax—pro
- composition
- 60% keratin, 12–20% fatty acids and alcohols, 6–9% cholesterol
- types
- Wet (dominant) and dry (recessive), determined by a single base change in the ATP-binding cassette C11 gene
- wet_type_lipid_content
- About 50% lipid
- dry_type_lipid_content
- About 20% lipid
- pH
- Typically around 6.1
- common_in
- Wet type: Africans, Europeans, Ainu; Dry type: some East Asians, Southeast Asians, Native Americans
Lore & Background
Cerumen is produced in the cartilaginous outer third portion of the ear canal, a mixture of secretions from sebaceous glands and modified apocrine sweat glands. There are two genetically-determined types: wet (dominant) and dry (recessive). Wet earwax is light or dark brown, viscous, and about 50% lipid; dry earwax is gray or tan, brittle, and about 20% lipid. The distinction is caused by a single base change in the ATP-binding cassette C11 gene. Dry-type individuals are homozygous for adenine (AA), while wet-type requires at least one guanine (AG or GG). Some East Asians, Southeast Asians, and Native Americans are more likely to have the dry type; Africans, Europeans, and other East Asians (including Ainu) are more likely to have the wet type.
Reader's Guide
Earwax plays a crucial role in ear health, providing lubrication, antimicrobial effects, and a self-cleaning mechanism via epithelial migration aided by jaw movement. Its antimicrobial properties, due to saturated fatty acids, lysozyme, and slight acidity (pH ~6.1), reduce viability of bacteria such as Haemophilus influenzae and Staphylococcus aureus, though some studies note cerumen can also support microbial growth. Excess or impacted cerumen can cause hearing loss, pain, tinnitus, and dizziness, and is more common in those with Down's syndrome. Treatment includes cerumenolytics (e.g., olive oil, sodium bicarbonate), microsuction, and irrigation, though cotton swabs are not recommended as they push wax deeper. The American Academy of Otolaryngology discourages removal unless symptomatic. Earwax is estimated to cause 60–80% of hearing aid faults.
Did You Know?
- Earwax can be many colors, including brown, orange, red, yellowish, and gray.
- Wet-type earwax is associated with armpit odor, which is increased by sweat production.
- Dry earwax is gray or tan and brittle, and is about 20% lipid.
- Earwax is estimated to be the cause of 60–80% of hearing aid faults.
More in Sensory Systems 1-24
Elsewhere in the Sensory Systems universe
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record