HS is a systemic inflammatory skin condition that often affects hair follicles and sweat glands. While the exact cause is unknown, it is thought that an overactive immune system produces too much inflammation throughout the body—not just the skin. HS usually affects areas where the skin rubs together, often starting around a hair follicle, causing it to become blocked.

In HS, it is thought that an overactive immune system
attacks blocked hair follicles.

Swollen Hair Follicle

Inflammation can cause hair follicles to become blocked and enlarged.

Ruptured Hair Follicle

Blocked and enlarged hair follicles can rupture, causing painful bumps, boils, and sores (abscesses).

Leaked Hair Follicle

These sores may leak blood and pus and can connect, forming tunnels that may lead to scarring.

It is also thought that the overactive immune system will attack other blocked hair follicles, starting the cycle all over again. This vicious cycle can lead to painful bumps (or inflammatory nodules), abscesses, and eventually may cause scarring.

Woman Crossed Arms

What HS is not:

HS is not caused by poor hygiene. HS is not a rash, and it's not contagious. While HS is not curable, the condition can be managed with proper treatment.

HS is not your fault. It can happen to almost anyone.

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You're not alone.
1 in 100
in the United States may
be affected by HS.

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Up to
have a family member with the condition.

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Women are
more likely to
develop HS.

HS may run in the family. The condition is mostly seen in women, and disproportionately affects people of color. Other factors thought to contribute to HS include one's weight and smoking.

HS almost exclusively occurs after puberty, usually beginning in a person's 20s, but in rare cases can start as early as puberty or as late as their 50s.

Hormonal changes may also contribute to the development of HS symptoms, and can make symptoms worse. In fact, HS is more common in women with polycystic ovary syndrome, a condition that causes hormonal imbalances. Some women may also experience HS flares around the time of their menstrual period.


There's hope when it comes to managing HS symptoms. Talk to an HS-treating dermatologist about options that may be right for you.