Acne occurs when hair follicles (or pores) become clogged with dead skin cells, sebum, bacteria, or a combination of all three. It is the most common skin condition in the United States, affecting as many as 50 million Americans each year.
Acne is a skin condition characterized by clogged pores. When pores get clogged, it causes red lesions — which you know as pimples — to form on the face or other areas of the body, especially those with the most oil glands, like the back, shoulders, or scalp.
While many people associate acne with teenagers, it can and does affect people of all ages.
Keep reading to uncover what acne can look and feel like, what causes it, and how acne is diagnosed and treated.
There are several types of acne that look slightly different, but have similar causes. There are non-inflammatory acne types, which include different kinds of pimples like whiteheads and blackheads, and inflammatory acne types, like papules, pustules, nodules, and cysts. There are also a few types of acne that fall outside either category.
We’ll start with the all the types of “acne vulgaris”:
Whiteheads (closed comedones): Whiteheads are small flesh-colored or white bumps that tend to feel very “poppable.” They occur when pores get clogged with sebum and dead skin cells and remain closed at the skin’s surface. Typically, whiteheads are not painful.
Blackheads (open comedones): Blackheads are small dark brown or black spots, often on the nose and chin. They happen when pores are clogged with sebum and dead skin cells, and are open at the surface. This exposes them to air and causes oxidation, which turns them black.
Papules: Papules are small, red, tender bumps that can be painful. They should not be squeezed to avoid worsening inflammation and scarring.
Pustules: Pustules are red bumps with white or yellow pus-filled centers (as the name suggests). They happen when pores become clogged and inflamed and then filled with fluid.
Nodules: Nodules are large, hard lumps beneath the skin’s surface. These are often painful and cause inflammation above and below the skin’s surface.
Cysts: Cysts are large, soft, pus-filled lesions beneath the skin’s surface. Also called cystic acne, this type of acne can cause severe inflammation and even infection.
Those aren’t the only marks you may notice on your skin, though. There’s also:
Acne Mechanica: Small, raised bumps caused by friction, heat, and pressure on the skin. It can result from wearing sports equipment, tight clothing, or headgear.
Acne Rosacea: While it’s technically a different condition, rosacea is often confused with acne. It manifests as small red bumps and is often accompanied by redness or broken blood vessels. It’s most common in adults over 30.
Acne is generally harmless from a physical health standpoint, but many studies indicate that the condition can affect self-esteem and quality of life.
Learning to recognize the symptoms of acne can help you begin an acne treatment before it gets worse (and more difficult to treat).
Symptoms of acne include:
Pimples, including whiteheads, blackheads, and pustules
Inflamed skin that is painful to the touch
Redness
Dark spots
Lowered self-esteem
While most of us are familiar with their appearance, many people wonder how pimples and pustules are formed. Research suggests that a combination of three factors — sebum, dead skin, and bacteria — typically causes breakouts.
Sebum: Sebum is an oily substance produced by sebaceous glands in the skin. While sebum plays a crucial role in keeping the skin moisturized and protected, it can also contribute to the development of acne when produced in excess. Genetics, hormonal changes (specifically increased levels of androgens), stress, environmental factors, and improper skin care can all lead to excessive sebum production. Too much sebum can mix with dirt, dead skin cells, makeup, or bacteria and clog pores, leading to breakouts.
Bacteria: Bacteria use sebum as a source of energy. So when there’s excess sebum, it’s a dream for bacteria — a dream that can cause severe acne. Bacteria that gets into the hair follicle and becomes inflamed or infected results in deep, painful cysts below the skin.
Dead skin: When dead skin cells build up in pores, it can cause breakouts. This can happen when sebum levels are normal, but elevated sebum levels paired with excess dead skin cells are a tried-and-true recipe for acne.
While excess sebum, dead skin, and bacteria cause acne physically, there are many factors that cause breakouts. We call these acne risk factors, which we’ll outline below.
Acne is commonly considered an adolescent rite of passage. But while it’s true that 85 percent of people between the ages of 12 and 24 experience at least some degree of acne, that has less to do with age itself than the fact that adolescence corresponds with puberty and hormonal changes.
In truth, acne can occur in people of all ages, and its prevalence in adults is increasing — the American Academy of Dermatology says acne affects up to 15 percent of women, though some studies put that number even higher.
Research also shows that adult acne is more common in women. In a 2018 survey of 1,013 people, the following percentages of women reported having acne:
Almost 5 percent of women ages 20 through 29
35 percent of women ages 30 through 39
26 percent of women age 40 through 49
15 percent of women over 50
The study also identified two subtypes of adult acne: persistent acne, which continues from adolescence into adulthood, and late-onset acne, which appears in those aged 25 and older who were not previously affected by acne vulgaris.
It’s no secret that pregnancy, periods, and puberty can wreak havoc on the skin. These are all tied to hormonal fluctuations.
For example, puberty and the first two trimesters of pregnancy increase the amount of androgens in the body, which increases sebum production and can lead to breakouts. Estrogen and progesterone drop right before your period starts, which can also cause breakouts.
Endocrine disorders disrupt hormones, which can impact skin. These conditions include:
Polycystic ovarian syndrome (PCOS): This condition creates excess androgens in the body and causes irregular menstrual cycles, unwanted hair growth, and acne.
Cushing syndrome: This condition occurs when the body produces too much of the hormone cortisol. Cortisol can increase oil production and contribute to acne development.
Androgen-secreting tumors: These are rare tumors that produce androgens and can cause acne in both men and women (though the tumors are more common in women).
There’s no gene for acne, per se, but your genetics influence how prone you are to breakouts.
For example, some research shows that genetics play a role in how effectively your immune system fends off a bacteria known as Propionibacterium acnes (P. acnes) that causes acne.
A large study on the DNA of 26,722 people found genetic variations in 15 genome regions (parts of genetic material) that were more common in people with severe acne. Basically, if you have a family history of acne, you’re more prone to it yourself.
Some medications and supplements can cause what’s called “drug-induced acne.” These include:
Vitamin B12
Thyroid hormones
Halogen compounds (iodine, bromine, fluorine, and chlorine)
Antibiotics (tetracycline and streptomycin)
Antituberculosis drugs (INH)
Lithium carbonate
High doses of oral corticosteroids
Antiepileptic drugs (phenobarbital and hydantoin derivatives)
Cyclosporin A
Antimycotics
Gold salts
Isotretinoin (an anti-acne drug that can cause an initial purge)
Clofazimine
Epidermal growth factor receptor inhibitors
Interferon-beta
Supplementing with testosterone may also cause acne because of the hormone’s effect on sebum levels.
Being exposed to germs and bacteria is a part of life, but there are things you can do to reduce the amount of bacteria that gets on your face, where it can cause acne.
Clean your makeup brushes regularly (regular soap and water are fine), wash your bedding frequently, and wipe your phone down to avoid introducing unnecessary bacteria onto your face.
Friction from clothes, headwear, or accessories can cause acne. This includes things we may not think twice about, like leggings, helmets, tight collars, and backpacks. Heat and sweat may also exacerbate this.
Sometimes, heavy oil-based skincare and makeup products (like thick foundations or rich moisturizers) can clog pores, leading to breakouts.
But oily products aren’t the only culprits here. Products that contain alcohol can be drying to the skin, leading to an overproduction of oil as the skin attempts to balance. Certain occlusive products with ingredients like petrolatum and mineral oil create a barrier on the skin that can trap bacteria and sebum in the pores, causing acne.
Look for makeup and skincare products marketed as “noncomedogenic,” which means they are formulated without pore-clogging ingredients. And this may be obvious, but you should avoid using expired products that may introduce bacteria onto the skin’s surface.
The link between diet and acne isn’t entirely understood, but it’s thought that some foods can contribute to acne, including:
High-glycemic-index foods: These are foods that raise blood sugar quickly. Research suggests that blood sugar and insulin spikes can cause inflammation throughout the body, potentially leading to acne. You’ve almost definitely heard that chocolate causes acne, but it’s not the chocolate itself, but rather the blood sugar spike (and, potentially, the milk, which we’ll cover next).
Dairy products: Cow’s milk specifically has been linked to acne. One study found that high school-aged females who drank two or more glasses of skim milk daily were 44 percent more likely to have acne than those who didn’t.
Foods high in saturated fat: This includes foods like red meat, cheese, butter, and hydrogenated oils. Some research has indicated that more acne lesions are present when the ratio of saturated to monosaturated fats (like those found in avocado or olive oil) is higher. Acne can also sometimes be caused by coming into contact with grease (like cooking with frying oil).
You’ll typically know whether or not you have acne. However, if you’ve been using over-the-counter products and your acne is not improving (or is getting worse) or you’d rather skip the guessing game of what helps acne and get expert support, seeing a dermatologist is the best way to diagnose acne.
They’ll be able to tell what type of acne you’re experiencing, help you learn your acne triggers, and teach you how to treat acne — whether it’s suggestions for lifestyle changes, certain products, or prescription treatments. They’ll also provide suggestions for how to reduce or manage scarring.
If you’re wondering how to cure acne, you’ll be happy to hear that acne is usually very treatable. Oral and topical acne treatments reduce oil and sebum production or treat the bacteria, either of which should result in clearer skin.
Topical prescription treatments are typically applied directly to clean, dry skin once or twice a day. Retinoids — a form of vitamin A that dries out the skin, helps unclog pores, and reduces the amount of dead skin cells — are a commonly prescribed one.
Topical prescription retinoids include:
Tretinoin (Retin-A®): Reduces inflammation and prevents clogged pores
Adapalene (Differin®): Often less irritating than other retinoids, it’s sometimes prescribed to those with acne and sensitive skin
Tazarotene (Tazorac®): Prevents skin cells from building up and reduces inflammation, though it can be irritating
Using a moisturizer alongside a retinoid is usually recommended to avoid over-drying the skin.
Oral retinoids are also available. Isotretinoin is a powerful retinoid typically reserved for severe acne that hasn't responded to other treatments. It works by reducing oil production, unclogging pores, and reducing inflammation.
Antibiotics for acne kill bacteria on the skin. They can be used topically or taken orally, and they’re usually prescribed alongside a retinoid for help drying out existing acne and benzoyl peroxide, which reduces the likelihood of developing antibiotic resistance. Commonly prescribed antibiotics for acne include:
Tetracycline (minocycline, doxycycline)
Macrolide (erythromycin, azithromycin)
Topical Clindamycin
Topical Erythromycin
Prescription medications that are not classified as antibiotics are also prescribed for acne. We’re talking:
Hormonal Birth Control: Contraceptives may not be top of mind when it comes to treating acne, but it’s sometimes prescribed precisely for that reason. The pill reduces the number of androgens, or male sex hormones, produced by your body.
Spironolactone: Spironolactone is used to treat high blood pressure but is also prescribed off-label for treating acne in women. Spironolactone reduces the amount of androgen hormones in your body, which cuts down sebum production. Its effects on hormones are so pronounced that it is not recommended for treating acne in men because of its potentially feminizing side effects.
If you’ve been to a drugstore recently, you already know that there are tons (and tons) of products designed to treat acne. Below are some over-the-counter ingredients that are known to be effective in treating mild to moderate acne on the surface of the skin (though, in some cases, dermatologists may prescribe over-the-counter products for more severe forms of acne).
Retinol: Many retinol products are available over the counter. These have a lower strength than prescription treatments.
Benzoyl Peroxide: Benzoyl peroxide reduces bacteria on the skin. It also helps to dry existing pimples and shed dead skin cells. Unfortunately, this ingredient has a bleaching effect that can stain clothes and towels.
Chemical Exfoliants: Manual exfoliants (think gritty scrubs) can be too harsh on acne. Chemical exfoliants like alpha-hydroxy acid or AHAs (lactic acid, glycolic acid, and azelaic acid, to name a few) and beta-hydroxy acid or BHAs (salicylic acid) can slough off dead skin without being overly harsh. Salicylic acid can also combat enlarged pores and fine lines, and is very good at penetrating and unblocking pores. Chemical exfoliants can also help reduce acne scarring and dark spots.
Some people turn to acne treatment therapies instead of (or in addition to) acne medication or over-the-counter products. These include:
Light Therapy: Light therapy treats acne by employing specific wavelengths of blue or red light to target the bacteria and reduce inflammation associated with acne. More research is needed on its effectiveness, but limited research shows some promise.
Chemical Peels: This procedure, done in a dermatologist’s or esthetician’s office, delivers high doses of chemical skincare ingredients to the skin. This causes the top layer of skin to shed (or “peel,” hence the name) and reveals brighter, more even skin.
Steroid Injections: In some cases, a dermatologist may inject a steroid treatment directly into a pimple, quickly reducing pain and making the breakout less noticeable. This can be helpful for extremely painful cysts or nodules. It’s also an effective way to treat a pimple that pops up at the wrong time (say, during the week of your wedding). However, research shows that topical steroids and steroid injections can thin and discolor the skin over time.
It’s always a good idea to talk to your doctor before starting any acne treatment, even if it’s over-the-counter. This is especially true for those who are pregnant or breastfeeding, as many acne-fighting ingredients (including retinol and salicylic acid) are not recommended in pregnancy.
Also important to know: Most acne treatments typically take at least a few weeks to show results, and some may cause an initial “purge” in which the skin gets worse before it gets better.
Some acne is inevitable (thanks to good old genetics and hormones). The bright side? There are ways to reduce and even prevent acne before it starts. Here’s how:
Cleanse regularly. Ideally, you’d wash your face twice daily with a gentle, non-comedogenic cleanser to remove excess oil, dirt, and impurities without over-drying your skin.
Avoid touching your face. Keep your hands away from your face to prevent the transfer of bacteria and oils.
Use non-comedogenic products. Choose skincare and makeup products that are less likely to clog pores.
Maintain a balanced diet. Eat a variety of fruits, vegetables, whole grains, and lean proteins. Avoid high-glycemic-index foods, sugary snacks, and excessive dairy intake (especially skim milk), which can exacerbate acne.
Stay hydrated. Drink plenty of water to keep your skin hydrated.
Avoid heavy or greasy products. Heavy creams and greasy hair products can transfer to your face and clog pores.
Use clean makeup brushes. Regularly wash your makeup brushes and applicators to prevent the buildup of bacteria, oil, and product residue that can cause breakouts. You’ll want to avoid sharing makeup products as well.
Keep your pillowcases clean. Change your pillowcases frequently to prevent the accumulation of oil, dirt, and bacteria that can transfer to your skin while you sleep.
If you’re unsure of how to treat your acne or you want to speak to a healthcare provider but don’t have an established relationship with a dermatologist, you can connect with a healthcare provider online through our platform to start addressing your acne concerns today.