Types of acne: how to tell each one apart

Acne is one condition with several types of spot. The NHS names six: blackheads, whiteheads, papules, pustules, nodules and cysts, and it says you may have more than one type at once. The American Academy of Dermatology (AAD) says each type needs a different treatment, so knowing which ones you have is the first step. This guide explains each type, how to tell them apart, how doctors grade acne, which look-alike conditions get mistaken for it, and which types need a doctor. Each type and body area has its own guide in this hub, listed at the end of the page.

Skinli is an education site and is not a doctor. Every medical statement below names its source.

How every type starts

All acne starts the same way. NIAMS, part of the US National Institutes of Health, says acne happens when hair follicles, the small tubes in the skin that hold each hair, become clogged. Oil and dead skin cells stick together and plug the pore. What happens next decides the type:

• If the plug stays in place with no swelling, you get a blackhead or whitehead.
• If bacteria grow in the plug and the area swells, you get a papule or pustule.
• If the swelling goes deep into the skin, you get a nodule or cyst.

The AAD puts it in one sentence: acne develops when pores become clogged, and the type of acne depends on what clogs them. The guides on what acne is and what causes acne cover this process and its triggers in full.

The six types at a glance

Type	What it looks like	Red and swollen	Depth
Whitehead	A small raised bump, white or skin-colored	No	In a pore sealed at the top
Blackhead	A dark dot, usually flat	No	In a pore open to the air
Papule	A small red bump that feels hard; may look brown or purple on brown and black skin	Yes	Deeper than a plug
Pustule	A red bump with a white or yellow center of pus	Yes	Deeper than a plug
Nodule	A large, hard, painful lump with no pus	Yes	Deep in the skin
Cyst	A large, painful lump with pus, softer than a nodule	Yes	Deep in the skin

The descriptions come from the AAD, NIAMS and the NHS, as set out below.

Whiteheads and blackheads

These are the mildest types. Doctors call them comedones, which means clogged pores. The AAD gives the medical names: a whitehead is a closed comedo ("closed pore") and a blackhead is an open comedo ("open pore").

A whitehead forms when oil and dead skin cells plug the opening of a pore, the AAD says. The plug stays under the skin and shows as a raised bump. A blackhead forms when the buildup widens the opening. The plug meets the air, and a chemical reaction turns it dark, which the AAD compares to a cut apple turning brown. NIAMS gives the same reason: air changes the color of the oil at the surface.

The AAD recommends a retinoid to unclog pores, such as adapalene, which you can buy without a prescription, plus a benzoyl peroxide wash. It says to give treatment six to eight weeks. The blackheads vs whiteheads guide covers both in detail.

Papules and pustules

These are what most people call pimples. The AAD explains that when oil, bacteria and dead skin cells push deeper into the skin, the area becomes red and swollen.

• A papule is a small red bump without pus. The AAD says papules feel hard, and many of them can make skin feel like sandpaper. NIAMS says they can be tender to the touch.
• A pustule is a papule with pus. The AAD says you often see a yellow or white center. NIAMS says it may be red at the base.

The AAD recommends washing with an acne product that contains benzoyl peroxide or salicylic acid, and not popping pustules, because popping can make acne worse. If there is no improvement in six to eight weeks, it suggests seeing a dermatologist. Salicylic acid vs benzoyl peroxide explains how to choose between the two.

Nodules and cysts

These are the deepest and most serious types. The AAD says a nodule or cyst forms when the swelling in a clogged pore goes deep into the skin, which is why they feel tender or painful. The main difference, it says, is that a cyst contains pus, so it feels softer, while a nodule has no pus and feels harder.

NIAMS calls acne with these lumps severe nodular acne and says it is sometimes called cystic acne. The AAD says nodules and cysts often cause permanent scars as they heal, and that anyone with this type of acne needs a dermatologist's help. The cystic acne guide explains the causes and what doctors offer.

How doctors grade acne

The UK NICE guideline sorts acne by counting spots in three groups:

Band	What it includes
Mild to moderate	Any number of blackheads and whiteheads, up to 34 inflamed spots, and up to 2 nodules
Moderate to severe	35 or more inflamed spots, or 3 or more nodules

NICE also tells doctors to refer people with nodulo-cystic acne, or where the diagnosis is uncertain, to a team led by a consultant dermatologist. The 2024 US acne guideline in the Journal of the American Academy of Dermatology strongly recommends isotretinoin, a prescription medicine, for acne that is severe, causes scarring, or has not responded to other treatment.

Where acne appears

The NHS says acne usually affects the face, chest and back. MedlinePlus adds that it may also occur on the arms, legs and buttocks. Each area has its own triggers, and this hub has a guide for each: back acne, chest acne, butt acne, a pimple on the lip, a pimple on the nose, and forehead and chin acne.

Acne along the jawline and lower face in adult women can be hormonal. Skinli's existing guide on hormonal acne vs regular acne covers that pattern.

Conditions that look like acne

Several conditions produce bumps that look like acne but need different care. The AAD's stubborn acne page names six, and it has a separate page on folliculitis:

• Fungal acne. A yeast infection of the hair follicles. A 2025 review in the Journal of Fungi says it causes small, itchy bumps that all look alike, with no blackheads, whiteheads, nodules or cysts, and that it is often misdiagnosed as acne. See fungal acne.
• Folliculitis. An infection of the hair follicles that usually looks like a sudden acne breakout, with a red ring around each spot, the AAD says.
• Rosacea. Acne-like breakouts where the face is red, with skin that may sting or burn.
• Keratosis pilaris. Small, rough bumps on the upper arms and front of the thighs.
• Hidradenitis suppurativa. Pimple-like bumps or deep, acne-like cysts where skin touches skin, such as the armpits, groin and buttocks.
• Perioral dermatitis. Many small bumps only around the mouth, sometimes around the eyes or nose.
• Polycystic ovary syndrome (PCOS). A hormone condition in which acne comes with other signs, such as hair loss on the head or extra hair on the face.

The AAD says that if stubborn acne looks like any of these, a dermatologist can give the right diagnosis.

Which types need a doctor

Blackheads, whiteheads and a few pimples can often be treated at home. See a doctor or dermatologist if:

• You have nodules or cysts. The AAD says deep, painful acne needs a dermatologist, and store-bought treatment cannot clear severe acne.
• Spots leave scars. The AAD says the sooner treatment starts, the fewer permanent scars you will have.
• A product has had six to eight weeks without improvement, the AAD's point for getting help.
• You see signs of a skin infection, such as hot, swollen and red skin, which the NHS lists.
• The bumps itch, all look alike, or appear in skin folds, which may point to a look-alike condition.
• Acne affects your mood. The NHS says to see a GP if acne is affecting your mental health.

For blackheads, whiteheads and ordinary pimples, the complete acne skincare routine gives the daily steps, and how to start adapalene without irritation covers the retinoid the AAD recommends. Skinli's photo check can look at one photo, ask two questions, and suggest a starting plan that flags when a doctor should look.