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A B C D E F G H I J K LM N O P Q R S T U V W X Y Z 0-9
(A-Z listing includes diseases, conditions, tests and procedures)


What is acne?

Acne is a disorder of the hair follicles and oil glands (sebaceous glands). The sebaceous glands secrete oils (sebum) to keep the skin moist. When the glands get clogged, it can lead to pimples and cysts.

Acne is very common. People of all races and ages have acne. In fact, most people in the U.S. between 11 and 30 years old will be affected by it. Even people in their 40s and 50s can have acne. However, acne most often begins in puberty. During puberty, the male sex hormones (androgens) increase in both boys and girls. This causes the sebaceous glands to produce more oil.

Normally, the sebum produced travels through the hair follicles to the skin. However, skin cells can plug the follicles. This can block the sebum. When follicles become plugged, skin bacteria begin to grow inside the follicles. Inflammation and pimples then develop. The most common types of pimples are:

  • Whiteheads. These pimples stay under the skin's surface.

  • Blackheads. These rise to the surface of the skin. Although these pimples are black, the color is not from dirt. It's from the process of oxidation when the sebum is exposed to air. 

  • Papules. These are tender, small pink bumps.

  • Pustules.  Pimples that have pus on the top and are red on the bottom of the lesion.

  • Nodules. These are hard, large, painful pimples that arise deep in the skin.

  • Cysts.  Pus-filled, deep, painful pimples that often result in scars. 

The basic acne lesion is called a comedo.

Got Adult Acne? Get Answers from an Expert

Woman picking at her skin

Acne isn't confined to the teenage years. Adults can get it too, and women tend to have adult acne more often than men. Learn what may be causing your acne — and how to treat it.

Read more.

What causes acne?

Rising hormone levels during puberty may cause acne. Also, acne is often inherited. Other causes of acne may include the following:

  • Hormone level changes during a woman’s menstrual cycle

  • Hormone changes during pregnancy

  • Starting or stopping birth control pills

  • Certain drugs (such as corticosteroids, lithium, and barbiturates)

  • Oil and grease from the scalp, mineral or cooking oil, and certain cosmetics

Squeezing the pimples or scrubbing the skin too hard can make acne worse. Skin may also become irritated with friction or pressure from helmets, backpacks, or tight collars. Pollution or humidity can also irritate the skin.

What are the symptoms of acne?

Acne can appear as pimples without abscesses or pus-filled cysts that rupture and result in larger abscesses. It can occur anywhere on the body. However, acne most often appears in areas where there is a high concentration of sebaceous glands, including:

  • Face

  • Chest

  • Upper back

  • Shoulders

  • Neck

Acne may look like other skin conditions. Always consult your health care provider for a diagnosis.

How is acne diagnosed?

Your health care provider can usually diagnose acne by examining your skin.

How is acne treated?

Your health care provider will consider your age, overall health, the severity of the acne and other factors in determining what treatment is best for you.

Treatment for acne focuses on minimizing scarring and improving appearance. Treatment for acne may include medications you apply to your skin or medicine you take in pill form. Some of these medicines need to be prescribed by your health care provider. In some cases, a combination of both types of medications may be advised.

Medications you apply to the skin are often prescribed to treat acne. These may be in the form of a cream, gel, lotion, or solution. Examples include:

Benzoyl peroxide

Kills the bacteria


Helps stop or slow down the growth of the bacteria and reduces inflammation


Stops the development of new acne lesions and encourages cell turnover, unplugging pimples


Decreases acne formation

Acne medications you take by mouth, or oral antibiotics, are often prescribed to treat moderate to severe acne, and may include the following:

  • Doxycycline

  • Erythromycin

  • Tetracycline

Isotretinoin is a prescription drug taken by mouth for severe, cystic, or inflammatory acne. It is used when other methods can’t  prevent extensive scarring. Isotretinoin reduces the size of the sebaceous glands that produce the skin oil. It also increases skin cell shedding, and affects the hair follicles. These effects reduce the development of acne. Isotretinoin can clear acne in 85% of people who use it.  However, the drug has major side effects, including psychiatric side effects. It is very important to discuss this medication with your health care provider.

Women who are pregnant or who are able to become pregnant must not take isotretinoin. It can cause birth defects. Isotretinoin can also cause miscarriage or premature birth.

Your doctor can recommend specific steps to minimize acne scars.

Although acne often is a chronic condition, even if it lasts only during adolescence, it can leave lifelong scars. Acne scars typically look like "ice pick" pit scars or crater-like scars. Although proper treatment  may help minimize scarring, several dermatological procedures may help to further minimize any acne scars, including the following:

  • Dermabrasion.  This may be used to minimize small scars, minor skin surface irregularities, surgical scars, and acne scars. It involves removing the top layers of skin with an electrical machine that "abrades" the skin. As the skin heals from the procedure, the surface appears smoother and fresher.

  • Chemical peels. These are often used to minimize sun-damaged skin, irregular pigment, and superficial scars. The top layer of skin is removed with a chemical applied to the skin. By removing the top layer, the skin regenerates, often improving the skin's appearance.

  • Derma filler injections. These are injected beneath the skin to replace the body's natural collagen that has been lost. Injectable dermal fillers are generally used to treat wrinkles, scars, and facial lines.

  • Laser resurfacing.  This uses high-energy light to burn away damaged skin. It may be used to minimize wrinkles and fine scars.

  • Phototherapy or blue light therapy. Phototherapy using a blue light source. It has been shown to decrease the number of acne-causing bacteria with minimal side effects, such as dry skin.  Blue light therapy does not use ultraviolet (UV) light, so it does not damage the skin as earlier types of light therapy did.

  • Pulsed light and heat energy (LHE) therapy. This type of combined light and heat therapy is believed to work by destroying acne-causing bacteria. It also shrinks the oil-producing glands in the skin. The FDA has approved an LHE system that uses green light and heat pulses for treating mild to moderate acne.

  • Punch grafts. Punch grafts are small skin grafts used to replace scarred skin. A hole is punched in the skin to remove the scar, which is then replaced with unscarred skin (often from the back of the earlobe). Punch grafts can help treat deep acne scars.

  • Autologous fat transfer.  An autologous fat transfer uses fat taken from another site on your own body and injects it into your skin. The fat is placed beneath the surface of the skin to push up the depressed scars. This method is used to correct deep contour defects caused by scarring from severe acne. Because the fat may be reabsorbed into the skin over months, you may need to have it repeated.

What are the complications of acne?

Acne can leave lifelong physical scars. It can also cause self-esteem problems.

Can acne be prevented?

Acne is caused by normal hormonal changes that occur during puberty. This makes prevention of acne very difficult, or even impossible.

 However, avoiding substances that can cause acne may help. This includes certain medications (such as corticosteroids, lithium, and barbiturates), mineral or cooking oil, or certain cosmetics. Also, daily shampooing helps prevent oil and grease on the scalp from getting on your face or back. Early treatment of acne may prevent it from getting worse and causing scars.

When to seek medical care

Acne is a common condition. If you have acne that isn't helped with home care or is severe or leaving scars, see your health care provider.

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Skin cancer accounts for nearly half of all cancer cases. Protecting your skin from the sun is vital. It’s also important to examine your skin on a regular basis. Become familiar with moles or other skin conditions in order to better identify changes. If you or your family has a history of skin cancer, visit a dermatologist regularly for routine skin checkups.

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Key points

  • Acne is a disorder of the hair follicles and sebaceous glands which become clogged, leading to pimples and cysts.

  • Acne is a common condition that usually begins during puberty because of hormonal changes.

  • Acne can be either superficial or deep.

  • If untreated, acne can cause scaring that can last a lifetime.

  • Avoiding  substances that make acne worse, and early treatment of acne, can minimize or prevent acne scars.

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.

  • Bring someone with you to help you ask questions and remember what your provider tells you.

  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.

  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your provider if you have questions.

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