Acne | Causes & Risk Factors


What causes acne?

Acne occurs when a mix of dead skin cells and sebum block the hair follicles of your skin. There are a few different types of acne:

  • When the hair follicle becomes plugged with oil and skin cells, a “whitehead” forms in the hair follicle.
  • If the follicle is plugged near the surface of the skin and air touches the plug, it turns black and is called a "blackhead." A blackhead isn't caused by dirt.
  • If the wall of a plugged hair follicle breaks, the area swells and turns into a red bump. If the hair follicle wall breaks near the skin surface, the bump usually becomes a pimple.
  • If the follicle wall breaks deep in the skin, acne nodules or cysts can form. This is called "cystic acne."

Who gets acne?

Both boys and girls get acne. But it may be worse in boys because they have more skin oils. For many people, acne symptoms fade by the age of 25, but they can continue well into the adult years.

Family history also plays a role. If your mother and father had bad acne, you may have it, too.

Your immune system plays a role too. Some people are extra sensitive to the bacteria that get trapped in their hair follicles.

Things that often make acne worse

  • Hormonal changes, especially during puberty, before your monthly period (in women), or during pregnancy
  • Certain medications
  • Certain cosmetics, such as oil-based makeup, suntan oil, and hair products
  • Stress
  • Squeezing or picking at skin blemishes
  • Hard scrubbing of the skin

 Things that don't cause acne

  • Dirt
  • Chocolate or greasy foods
  • Sexual activity or masturbation

Written by editorial staff

Reviewed/Updated: 03/14
Created: 01/96