Key takeaways

  • About 95% of people aged 11 to 30 have acne to some extent. It often clears by the mid-20s, although about 3% of adults over 35 still have it. NHS
  • Poor hygiene is not the cause. Washing does not remove the blockage inside a hair follicle. NHS
  • Hormones increase sebum production and thicken the follicle lining. The resulting blockage and changes in skin bacteria produce inflamed spots. NHS
  • Treatment takes several months to work. Results are usually good once it starts working. NHS
  • Picking or squeezing can leave permanent scars. Blackheads are not dirt to be scrubbed out. NHS
  • Moderate or severe acne, nodules and cysts need a doctor. Cysts are pus-filled lumps resembling boils and carry the greatest scarring risk. NHS
  • Feeling very unhappy about acne is also a reason for medical help. See a doctor if pharmacy treatments have not controlled it. NHS

What do the different spots look like?

Acne includes blackheads, whiteheads, papules, pustules, nodules and cysts. The NHS distinguishes 6 main types. Blackheads are small black or yellowish bumps, coloured by the follicle lining. Whiteheads look similar but may be firmer and do not empty when squeezed.

Papules are small red bumps that may feel tender or sore. A pustule has a white centre of pus. Nodules are larger, hard and sometimes painful lumps beneath the surface; cysts are the large, pus-filled, boil-like lumps with the greatest risk of permanent scarring. NHS

The face is affected in almost everyone with acne. The NHS gives more than half for the back and about 15% for the chest. Skin may be oily, hot or painful to touch. NHS

What actually causes acne?

Hormones acting on the oil glands and on the lining of the hair follicle.

Certain hormones cause the glands beside hair follicles to produce more oil, or abnormal sebum, in the NHS explanation. That sebum changes the behaviour of P. acnes, a usually harmless skin bacterium, which becomes more aggressive and causes inflammation and pus. The same hormones thicken the inner lining of the hair follicle, blocking the pore.

Cleaning does not remove a blockage inside the follicle. The NHS finds no evidence that poor hygiene or sexual activity contributes to acne. Washing harder or more often irritates already inflamed skin. Treatment acts on the follicle and takes months rather than days.

Acne is also known to run in families. If both parents had acne, you are likely to as well. And hormonal changes during the menstrual cycle or pregnancy can trigger episodes in women, which is why adult acne in women often follows a monthly pattern.

Diet is not the established cause, and restriction does not replace treatment. Note any particular food that reliably worsens your acne for discussion.

Who gets it, and does it go away?

Most people, and usually yes.

About 95% of people aged 11 to 30 are affected to some extent. It is most common in girls from 14 to 17 and boys from 16 to 19. Most people have it on and off for several years before it improves, and it often disappears by the mid-20s.

About 3% of adults over 35 still have acne. The mechanism and treatment principles are the same in adult life; in women, a menstrual pattern can point towards hormonal treatment.

What are the treatments?

Topical treatments first, then oral options, escalating with severity. The skin care catalogue lists the treatments stocked here, also grouped under acne vulgaris.

Topical retinoids, including adapalene and tretinoin, act on the follicle blockage. The NHS treatment chapter describes them removing dead skin cells so they do not build up inside the follicles. These creams and gels can cause dryness and irritation in the first weeks and increase sun sensitivity. The NHS advises applying them 20 minutes after washing, sparingly across the affected facial areas, and avoiding excessive sun or UV exposure. NHS acne guide, treatment chapter

Benzoyl peroxide reduces bacteria and helps unblock pores, including blackheads and whiteheads. It is an antiseptic with an anti-inflammatory effect. The NHS lists dry or tense skin, stinging, itching, burning, redness and peeling among its common side effects. Keep it away from hair and fabric because it bleaches them, including towels and pillowcases. NHS acne guide

Azelaic acid is an alternative for people who cannot tolerate retinoids or benzoyl peroxide, and is often used where post-inflammatory pigmentation is a concern.

Topical antibiotics such as clindamycin are used for inflamed acne, generally combined with benzoyl peroxide rather than alone, to limit resistance.

Oral antibiotics such as doxycycline are used for moderate acne over months rather than days. Doxycycline carries its own practical rules, including a notable sun-sensitivity warning, covered in doxycycline.

Hormonal treatment is an option for some women, where the monthly pattern points at the driver.

Isotretinoin is the treatment for severe acne that has not responded to other options. It is prescribed and monitored by a specialist, and it carries strict requirements around pregnancy, because it causes serious birth defects. Anyone considering it needs that conversation in full with the prescriber rather than a summary here.

MedicForce option: our skin listings identify the active ingredient and strength, including acne treatments available in several concentrations.

When should I see a doctor?

For moderate or severe acne, for nodules or cysts, or when it is affecting how you feel.

The NHS advises medical review when:

  • if over-the-counter treatments do not control it
  • if it is making you feel very unhappy
  • if you have moderate or severe acne, or develop nodules or cysts, because these need proper treatment to avoid scarring

Deep, painful lumps need prompt treatment because preventing scars is much easier than treating them. Distress also justifies treatment in its own right; it need not accompany severe-looking acne.

What about scarring and marks?

Do not pick, and know the difference between a mark and a scar.

Picking and squeezing can leave permanent scars. A flat mark and a change in skin texture have different outlooks:

  • Post-inflammatory marks, flat brown or red patches left after a spot heals. These are pigment changes, they fade over months, and sun exposure makes them darker and slower to go. On brown and darker skin they are often the more distressing problem. Sun protection helps here, and the same principles as melasma apply.
  • True scars, where the skin texture has changed. These do not fade on their own and are treated separately.

Preventing both means treating the acne properly and early, and leaving spots alone.

Do and don’t

Do:

  • Give the follicle treatment the time your prescriber specified, usually several months: follicle behaviour changes slowly. Results are usually good once it works, but some treatments worsen acne initially.
  • Change one product at a time. If you start three together, you cannot identify which helped or caused irritation.
  • Use sun protection, especially with retinoids or doxycycline. For skincare, make-up and suncare, the NHS recommends water-based, non-comedogenic products instead of oil-based ones. NHS
  • Remove make-up before bed. For dryness, the NHS suggests a fragrance-free, water-based emollient. NHS
  • Shower promptly after exercise because sweat can irritate acne. Exercise can help mood and self-esteem even though it does not improve acne itself. Keep hair washed and off the face. NHS
  • See a doctor for nodules, cysts or acne affecting how you feel.

Don’t:

  • Wash affected skin more than twice daily. Use mild soap or cleanser and lukewarm water; very hot or cold water can worsen acne. NHS
  • Pick, squeeze or try to clean out blackheads.
  • Stop after four weeks and switch because it seems to have failed, the commonest reason treatment fails. Avoid introducing several new active treatments together.
  • Take isotretinoin without specialist supervision.