Acne is a skin condition where pores become clogged with oil and dead skin cells, causing bumps, blackheads, whiteheads, or deeper lesions

Acne forms when hair follicles under your skin fill with sebum (oil your skin makes naturally) and dead skin cells. The clogged pore can stay closed (blackhead or whitehead) or become inflamed and infected, creating the red, painful bumps most people recognize as acne. It is not caused by dirt, poor hygiene, or eating certain foods—though some factors can make it worse.

Acne most often appears on the face, chest, shoulders, and back because these areas have the most oil glands. It can range from a few occasional bumps to widespread, severe breakouts that leave scars. The condition is common in teenagers and young adults but can happen at any age.

Key Takeaways

  • Acne forms when oil and dead skin cells block hair follicles, and bacteria can make the blockage inflamed or infected.
  • Hormones, genetics, certain medications, and skin irritation all influence whether and how often you break out.
  • Acne is not caused by eating chocolate, skipping showers, or not washing your face hard enough.
  • Different types of acne—blackheads, whiteheads, papules, pustules, cysts—require different treatment approaches.
  • Severe acne can cause permanent scarring, so early treatment often prevents worse outcomes later.

How hormones trigger acne

Hormonal changes are the strongest driver of acne, especially during puberty. When androgen levels rise (in both boys and girls), oil glands enlarge and produce more sebum. This is why acne often starts in the teenage years and why it can flare during the menstrual cycle in people who menstruate.

Adults can also experience acne triggered by hormonal shifts—pregnancy, starting or stopping birth control, polycystic ovary syndrome (PCOS), and menopause all affect oil production. Stress hormones like cortisol can also increase sebum production and trigger breakouts, though stress itself does not cause acne.

Genetics and family history

If your parents had acne, you are more likely to have it too. Genetics influence how much oil your skin produces, how quickly your skin cells shed, and how your immune system responds to bacteria in clogged pores. This does not mean you will definitely break out, but it does mean your skin is predisposed to it.

Genetics also affect which type of acne you are more likely to develop and how severe it tends to be. Someone with a family history of severe cystic acne is more likely to experience it themselves than someone whose relatives had only occasional whiteheads.

Medications and products that can trigger acne

Certain medications cause acne as a side effect. Corticosteroids (used for inflammation and autoimmune conditions), lithium (used for bipolar disorder), and some hormonal contraceptives can all increase breakouts. If you suspect a medication is causing acne, talk to the doctor who prescribed it—stopping or switching is sometimes possible, but never stop a medication on your own.

Skincare and cosmetic products can also clog pores. Heavy moisturizers, thick foundations, and oils labeled "non-comedogenic" (meaning they should not clog pores) sometimes still do. Sunscreen, hair products, and even fabric softener can trigger acne in people with sensitive skin. Switching products one at a time and waiting two to four weeks between changes helps you identify what is causing the problem.

The different types of acne and what they look like

Non-inflammatory acne includes blackheads and whiteheads. Blackheads are open pores clogged with oil and dead skin that look dark because of oxidation, not dirt. Whiteheads are closed pores with the same contents but covered by skin, so they appear as small flesh-colored or white bumps. Both are mild and usually do not cause pain or scarring.

Inflammatory acne includes papules (small red bumps), pustules (red bumps with a white or yellow center), nodules (large, painful bumps under the skin), and cysts (deep, fluid-filled lesions). Inflammatory acne happens when bacteria multiply in a clogged pore and trigger an immune response. Nodules and cysts are the most severe forms and carry the highest risk of permanent scarring.

When acne causes scarring

Scarring happens when inflammation is deep enough to damage the skin's structure. Picking, squeezing, or popping acne—especially nodules and cysts—increases the risk of scarring. Even without picking, severe inflammatory acne can leave permanent marks or pitted skin.

Scarring is one reason dermatologists recommend treating moderate to severe acne early rather than waiting for it to clear on its own. Some scars fade over time, but others are permanent. Treatment options for existing scars exist (laser therapy, chemical peels, microneedling), but prevention through early acne treatment is more effective than trying to fix scars afterward.

What acne is not caused by

Acne is not caused by poor hygiene or not washing your face enough. In fact, over-washing or scrubbing your skin too hard can irritate it and make acne worse. Bacteria living on your skin are normal and do not cause acne by themselves—the problem is bacteria trapped inside a clogged pore where your immune system cannot reach them easily.

Eating chocolate, greasy food, or sugar does not directly cause acne, though some research suggests high-glycemic foods (white bread, sugary drinks) and dairy may trigger breakouts in some people. The relationship is individual and not universal. Acne is also not contagious and cannot spread from one person to another through touch or sharing towels.

Frequently Asked Questions

Can acne go away on its own?

Mild acne sometimes clears without treatment, especially if it is triggered by a temporary factor like a new product. Moderate to severe acne rarely goes away without intervention and often worsens over time. Early treatment prevents scarring and reduces the duration of breakouts.

Is acne only a teenage problem?

Acne is most common in teenagers, but adults of any age can develop it. Adult acne is often hormonal (related to menstrual cycles, PCOS, or menopause) or triggered by medications, skincare products, or stress. It requires the same treatment approaches as teenage acne.

Does squeezing a pimple make it worse?

Yes. Squeezing pushes bacteria deeper into the skin and can cause more inflammation, redness, and swelling. It also increases the risk of scarring and infection. Leaving acne alone or using treatment products is more effective than trying to manually clear it.

Can stress cause acne?

Stress does not directly cause acne, but it can make existing acne worse by raising cortisol levels, which increase oil production. If you notice breakouts during stressful periods, stress may be a trigger for you, though it is usually not the only factor involved.

Is acne worse in summer or winter?

Acne patterns vary by person. Heat and humidity can increase oil production and sweat, worsening acne for some people. Others find acne improves in summer because sun exposure can temporarily dry out skin. Winter dryness and heavy moisturizers can trigger breakouts in different people. Tracking your own patterns helps identify your triggers.