What Is Acne?

Acne is one of the most common skin conditions in the world, and one of the most misunderstood. At its simplest, it is what happens when the skin's tiny oil glands and pores become blocked and inflamed. Understanding what is going on underneath takes a lot of the mystery, and the blame, out of it.

What is happening in the skin?

Your skin is covered in tiny pores, each connected to an oil gland. Acne begins when a pore becomes blocked by a mix of excess oil and skin cells that do not shed as they should. This trapped mixture creates the perfect environment for naturally present skin bacteria to multiply, and the body responds with inflammation. The result is the range of spots we recognise as acne.

What do the different spots mean?

Acne shows up in several forms, including blackheads and whiteheads (blocked pores), red papules and pus filled pustules (inflamed spots), and deeper, painful nodules and cysts (severe inflamed lesions beneath the skin). Most people experience a combination of these, and the balance helps a clinician assess both the severity and the most appropriate approach.

Who gets acne?

Almost everyone experiences acne at some point. It is extremely common during the teenage years, but it also affects many adults. Having acne is not a sign of poor hygiene, a bad diet or something you have done wrong. It is a medical condition with biological causes.

Frequently Asked Questions

Is acne just spots?

No. Acne ranges from blackheads and whiteheads to inflamed spots, nodules and cysts. It is a recognised medical condition rather than simply the occasional breakout.

Does everyone get acne?

Acne is extremely common, particularly during adolescence, but it can affect people of all ages, including many adults.

Is acne caused by being unclean?

No. Acne is driven by biological processes within the skin rather than poor hygiene. In fact, excessive washing can sometimes make acne worse.

Reviewed by Dr Tara Treacy, GP with a special interest in dermatology (IMC 411337).

Last reviewed: 16/07/2026.

General information only. It does not replace an individual medical assessment.