Sometimes, dead skin can clog up a hair follicle. That forces the hair inside it to grow sideways under the skin, rather than upward and outward. Sometimes, cutting naturally curly hair too closely will result in the sharpened end of the hair piercing the skin, causing an ingrown hair.
Ingrown hairs aren't serious. But they can be irritating and embarrassing.
What Does an Ingrown Hair Look Like?
An ingrown hair irritates the skin. It produces a raised, red bump (or group of bumps) that looks like a little pimple. Sometimes an ingrown hair can form a painful, boil-like sore.
Ingrown hairs can be itchy and uncomfortable, especially if you've got a lot of them. You may notice pus inside the bumps. Or you may see the hair that's causing the problem.
In men, ingrown hairs often pop up as a bunch of little bumps on the chin, cheeks, or neck after shaving.
In women, ingrown hairs are common on the legs, as well as in the pubic area and armpits. You can also get ingrown hairs on your buttocks.
Ingrown Hair Causes
Anyone can get an ingrown hair. But the problem is more common in people who have very curly or coarse hair. Curly hair is more likely to bend back and re-enter the skin, especially after it's been shaved or cut.
Also, people with high levels of certain sex hormones can have excessive hair growth, which makes it more likely to get ingrown hairs, especially after shaving.
Many African-Americans, Latinos, and people with thick or curly hair develop a type of ingrown hair called pseudofolliculitis. More commonly known as "razor bumps," this collection of little bumps is common on the beard area after you've shaved, waxed, or tweezed to remove unwanted hair. The hair that grows back has a sharper edge, so it can more easily poke back through the skin and get trapped under the surface.