The NIH News in Health
skip navigation
January 2010
(PDF—401 kb)  

Understanding Acne
How to Banish Breakouts

Cartoon of woman gently washing face.

There are many myths about what causes acne. Some people blame foods for their outbreaks. Some think that dirty skin causes it. But there’s little evidence that either has much effect on most people’s acne.

People of all races and ages get acne. About 4 of every 5 people between the ages of 11 and 30 have outbreaks at some point. It’s most common in adolescents and young adults. Although acne is usually not a serious health threat, it can be upsetting, and severe acne can lead to permanent scarring. Fortunately, for most people, acne tends to go away by the time they reach their 30s.

Acne begins in the skin’s oil glands. The oils travel up a canal called a follicle, which also contains a hair. The oils empty onto the skin surface through the follicle’s opening, or pore.

The hair, oil and cells that line the narrow follicle can form a plug and block the pore, preventing oil from reaching the skin’s surface. This mix of oil and cells allows bacteria that normally live on the skin to grow in plugged follicles. Your body’s defense system then moves to attack the bacteria and the area gets inflamed.

If the plugged follicle stays beneath the skin, you get a white bump called a whitehead. If it reaches the surface of the skin and opens up, you get a blackhead. It’s not because of dirt; the oil becomes black on the skin’s surface when it’s exposed to air. Both whiteheads and blackheads may stay in the skin for a long time. Eventually, the wall of the plugged follicle can break down, leading to pimples, or zits.

One important factor in acne is an increase in certain hormones during puberty. These hormones cause the oil glands to enlarge and make more oil. Hormone changes related to pregnancy or starting or stopping birth control pills can also cause acne.

Studies suggest that you can inherit a tendency to develop acne from your parents, so genes likely play some role. Stress doesn’t cause acne, but research has found that for people who have acne, stress can make it worse.

Certain drugs are also known to cause acne. Greasy cosmetics, for example, can alter the cells of the follicles and make them stick together, producing a plug. If you have acne, try oil-free cosmetics. Choose products labeled noncomedogenic (meaning they don’t promote the formation of closed pores).

If you have acne, don’t rub or touch your pimples. Squeezing, pinching or picking at them can lead to scars or dark blotches. Gently wash your face with a mild cleanser twice a day—and after heavy exercise. Don’t use strong soaps or rough scrub pads; they may make the problem worse. It’s also important to shampoo your hair regularly. If you have oily hair, you may want to wash it every day.

Several over-the-counter medicines can treat mild acne. It may take up to 8 weeks before you notice an improvement. For more severe acne, talk to your doctor about the options.

Researchers continue to work on developing new drugs to treat acne. They’re also trying to better understand the causes of acne so they can explore new remedies. In the meantime, there are several available treatments that may help.


Definitions iconDefinitions

A type of microbe.

Molecules sent through the bloodstream to signal another part of the body to grow or react a certain way.

Wise Choices iconWise Choices

Acne Flare-ups

The exact cause of acne is unknown, but certain factors can cause it to flare. They include:

  • Changing hormone levels in adolescent girls—and adult women 2 to 7 days before their menstrual period starts
  • Oil from skin products (moisturizers or cosmetics) or grease in the work environment (for example, a kitchen with fry vats)
  • Pressure from sports helmets or equipment, backpacks, tight collars or tight sports uniforms
  • Skin irritants, such as pollution and high humidity
  • Squeezing or picking at blemishes
  • Hard scrubbing of the skin
  • Stress

Links iconWeb Sites


What Is Acne?

to top    
NIH logo National Institutes of Health (NIH)
9000 Rockville Pike
Bethesda, Maryland 20892
DHHS logo Department of Health and
Human Services
  Office of Communications and
Public Liaison