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What is acne?

Acne is a disorder of the hair follicles and oil glands (sebaceous glands). The oil 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 ages 11 and 30 will be affected by it. Even people in their 40s and 50s can have acne. But acne most often starts in puberty. During puberty, the male sex hormones (androgens) increase in both boys and girls. This causes the glands to make more oil.

Normally, the oil made travels through the hair follicles to the skin. But dead skin cells can plug the follicles. This can block the oil. When follicles become plugged, skin bacteria start to grow inside the follicles. Inflammation and pimples then develop. The most common types of pimples are:

  • Whiteheads (closed comedones). These pimples are sealed over and have a small white pus-filled top.

  • Blackheads(open comedones). These pimples have a small black opening at the top. These pimples are black, but the color is not from dirt. It's from the process of oxidation when the oil is exposed to air. 

  • Papules. These are sore, small, pink bumps.

  • Pustules. These are pimples that have pus on the top and are red on the bottom of the lesion. These are signs of inflammatory acne. 

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

  • Cysts. These are pus-filled, deep, painful pimples that often leave scars. 

The basic acne lesion is called a comedone.

What causes acne?

Rising hormone levels during puberty may cause acne. Also, acne is often found in families. Other causes of acne may include:

  • Hormone level changes during a woman’s menstrual cycle

  • Hormone changes during pregnancy

  • Starting or stopping birth control pills

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

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

  • Diet may also play a role

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 high humidity can also irritate the skin.

What are the symptoms of acne?

Acne can appear as pimples without abscesses. Or it may appear as pus-filled cysts that break open (rupture) and result in larger abscesses. These may be painful or look unappealing. It can happen anywhere on the body, and it can be superficial or deep. But 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 see your healthcare provider for a diagnosis if you're not sure or need advice about treatment.

How is acne diagnosed?

Your healthcare provider can often diagnose acne by examining your skin.

How is acne treated?

Your healthcare 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 medicines you apply to your skin (topical) or medicine you take in pill form (oral). Some of these medicines need to be prescribed by your healthcare provider. In some cases, a combination of both types of medicines may be advised.

Medicines for the skin (topical medicines)

Medicines 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:

Type of medicine

How it helps

Benzoyl peroxide

Kills the bacteria and helps reduce the oil made by the sebaceous glands


Help stop or slow down the growth of the bacteria and reduce inflammation. Erythromycin, tetracyclines, and clindamycin are commonly used.


Stop the development of new acne lesions and encourage cell turnover, unplugging pimples. These include tretinoin, adapalene, and tazarotene.

Topical azelaic acid, salicylic acid, and dapsone are also often used.

Medicines taken by mouth (oral medicines)

Acne medicines you take by mouth, called oral antibiotics, are often prescribed to treat moderate to severe acne. These may include:

  • Doxycycline

  • Erythromycin

  • Tetracycline

  • Minocycline

  • Trimethoprim

  • Sulfamethasoxazole/trimethoprim

  • Dapsone

Spironolactone or birth control pills can be used by women to help offset the effect of androgens. These are hormones that cause acne to develop.

Isotretinoin (Accutane) is a powerful prescription medicine taken by mouth for severe, cystic, or inflammatory acne. It's used when other methods can’t prevent extensive scarring. Isotretinoin reduces the size of the sebaceous glands that make 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 most people who use it. But it sometimes has side effects, including potential psychiatric side effects. It's very important to discuss this medicine and all the potential side effects with your healthcare provider. Treatment is usually for 4 to 12 months. Regular blood testing is needed during treatment.

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.

Laser therapy and light therapy

Laser therapy or light therapy may be used to reduce the bacteria in the clogged pores.

  • Photodynamic therapy. This is a light-based procedure used to control moderate to severe acne.

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

  • Phototherapy using a blue light source. This has been shown to decrease the number of acne-causing bacteria with minimal side effects, such as dry skin. Blue light therapy doesn't use ultraviolet light, so it doesn't damage the skin as earlier types of light therapy did.

Procedures to treat acne scars

Acne is often a long-term (chronic) condition. But even if it lasts only during the teen years, it can leave lifelong scars. Acne scars typically look like "ice pick" pit scars or crater-like scars. Using the correct treatment may help reduce scarring. But there are also several dermatological procedures that may help to further reduce any acne scars, including:

  • Dermabrasion. This may be used to minimize small scars, minor skin surface irregularities, surgical scars, and acne scars. During this procedure, the top layers of skin are removed 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 reduce 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.

  • Dermal 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 reduce wrinkles and fine scars.

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

  • Autologous fat transfer. This treatment uses fat taken from another site on your own body that is injected 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. The fat may be reabsorbed into the skin over months. So you may need to have this procedure repeated.

What are possible 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 happen during puberty. This makes preventing acne very hard, or even impossible.

But it may be helpful to stay away from substances that can cause acne. This includes certain medicines (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 should I call my healthcare provider?

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

Key points about acne

  • Acne is a disorder of the hair follicles and oil (sebaceous) glands that become clogged. This leads to pimples and cysts.

  • Acne is a common condition that often starts during puberty because of hormonal changes.

  • Acne can be either superficial or deep.

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

  • Stay away from substances that make acne worse, and early treatment of acne, can reduce or prevent acne scars.

Next steps

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

  • Know the reason for your visit and what you want to happen.

  • 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 name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

  • Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

  • Ask if your condition can be treated in other ways.

  • Know why a test or procedure is recommended and what the results could mean.

  • Know what to expect if you do not take the medicine or have the test or procedure.

  • 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 or if an emergency occurs.

Online Medical Reviewer: Michael Lehrer MD
Online Medical Reviewer: Rita Sather RN
Online Medical Reviewer: Stacey Wojcik MBA BSN RN
Date Last Reviewed: 4/1/2023
© 2000-2024 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.