Ingrown hairs are hairs that have curled round and grown back into the skin. They produce raised red spots, which can sometimes become infected and turn into painful, pus-filled sores. Ingrown hairs can be itchy and embarrassing, but they often go away on their own. Anyone can get ingrown hairs, but they tend to be more of a problem in people with coarse or curly hair.
Ingrown hairs have usually grown out of the skin, curled back round and re-entered the skin. Some curl back into the hair follicle—small cavities in the skin that hairs grow out of—without even exiting the skin.
Ingrown hair can occur when the hair follicle becomes clogged with dead skin cells.
This forces the hair inside it to grow sideways, which is much more likely to happen if the hair is already curly or coarse and it’s recently been shaved.
Ingrown hairs can be a particular problem in the areas where you shave: the beard and scalp area in men, and the legs, armpits and pubic area in women. In these places, the hair that grows back has a sharper edge and can easily poke back into the skin.
Ingrown hairs look like pimples in the skin, and sometimes you can see the hair trapped beneath the skin. The spots can be filled with pus.