Earwax, also known by the medical term cerumen, is a waxy substance secreted in the ear canal of humans and other mammals. Earwax can be many colors, including brown, orange, red, yellowish, and gray. Earwax protects the skin of the human ear canal, assists in cleaning and lubrication, and provides protection against bacteria, fungi, particulate matter, and water.
Major components of earwax include cerumen, produced by a type of modified sweat gland, and sebum, an oily substance. Both components are made by glands located in the outer ear canal. The chemical composition of earwax includes long chain fatty acids, both saturated and unsaturated, alcohols, squalene, and cholesterol. Earwax also contains dead skin cells and hair.
Excess or compacted cerumen is the buildup of ear wax causing a blockage in the ear canal and it can press against the eardrum or block the outside ear canal or hearing aids, potentially causing hearing loss.
ABCC11
Cerumen is produced in the cartilaginous outer third portion of the ear canal. It is a mixture of secretions from sebaceous glands and less-viscous ones from modified apocrine sweat glands. The primary components of both wet and dry earwax are shed layers of skin, with, on average, 60% of the earwax consisting of keratin, 12–20% saturated and unsaturated long-chain fatty acids, alcohols, squalene and 6–9% cholesterol.
There are two genetically-determined types of earwax: the wet type, which is dominant, and the dry type, which is recessive. This distinction is caused by a single base change in the "ATP-binding cassette C11 gene". Dry-type individuals are homozygous for adenine (AA) whereas wet-type requires at least one guanine (AG or GG). Dry earwax is gray or tan and brittle, and is about 20% lipid. It has a smaller concentration of lipid and pigment granules than wet earwax. Wet earwax is light brown or dark brown and has a viscous and sticky consistency, and is about 50% lipid. Wet-type earwax is associated with armpit odor, which is increased by sweat production.