Symptom guide
Cyst, pimple, boil or ingrown hair?
All four are red, raised and sore, and all four get mistaken for each other. What separates them is how fast they arrive, how deep they sit and what’s on top. Answer five questions to see which yours most resembles.
Answer the five questions above and we’ll show which bumps yours most resembles, what usually helps, and when to come in.
The four pairs people confuse most, side by side. The drawings are slices through the skin, because depth is the clearest difference between them.
Ingrown hair vs cyst
| Feature | Ingrown hair | Cyst |
|---|---|---|
| How it starts | A few days after shaving, waxing or plucking | Slowly, over weeks or months |
| Depth | Shallow, right around the trapped hair | A round lump under the skin, moving slightly over the tissue below |
| Pain | Itchy or mildly tender | Usually none, unless it becomes inflamed |
| On top | Often a visible hair, loop or dark line under the skin | Often a tiny dark pore (punctum) in the middle |
| How long it lasts | Days to a couple of weeks; keeps returning if hair removal doesn't change | Months to years; flares and settles in the same spot |
The tell: Timing and the hair. An ingrown hair turns up a few days after shaving or waxing, sits right at the surface, and you can often see the hair. A cyst arrives slowly, sits as a round lump under the skin, and has been there for weeks — often with a tiny dark pore on top. A deep, inflamed ingrown hair is sometimes called an “ingrown hair cyst”, but it's usually inflammation around the hair rather than a true cyst, and it settles once the hair is free.
Boil vs cyst
| Feature | Boil | Cyst |
|---|---|---|
| How it starts | Over a few days, getting bigger and more painful | Slowly, over weeks or months |
| Depth | Deep, with hot, red, swollen skin around it | A round lump under the skin, moving slightly over the tissue below |
| Pain | Throbbing — usually the most painful of the four | Usually none, unless it becomes inflamed |
| On top | A yellow-white pus head forms as it ripens | Often a tiny dark pore (punctum) in the middle |
| How long it lasts | Roughly 1–3 weeks; may burst and drain | Months to years; flares and settles in the same spot |
The tell: Speed and pain. A boil goes from nothing to a throbbing, pus-filled lump in a few days. A cyst is usually painless and has been there for weeks or months. The confusing case is an inflamed cyst, which is red and sore like a boil — the clue is that the lump was there before it hurt.
Cyst vs pimple
| Feature | Cyst | Pimple |
|---|---|---|
| How it starts | Slowly, over weeks or months | Overnight, or over a day or two |
| Depth | A round lump under the skin, moving slightly over the tissue below | Usually at the surface; nodules sit deeper |
| Pain | Usually none, unless it becomes inflamed | Tender to press; deep ones throb |
| On top | Often a tiny dark pore (punctum) in the middle | A small white or yellow head, or nothing yet |
| How long it lasts | Months to years; flares and settles in the same spot | A few days to a week; deep ones longer |
The tell: How long it lasts. A pimple comes and goes within days to a week or two. A cyst is still there months later, feels like a smooth ball under the skin, and comes back in the same spot. Deep acne “cysts” are really inflamed nodules — a different thing from an epidermoid cyst, and treated differently.
Boil vs pimple
| Feature | Boil | Pimple |
|---|---|---|
| How it starts | Over a few days, getting bigger and more painful | Overnight, or over a day or two |
| Depth | Deep, with hot, red, swollen skin around it | Usually at the surface; nodules sit deeper |
| Pain | Throbbing — usually the most painful of the four | Tender to press; deep ones throb |
| On top | A yellow-white pus head forms as it ripens | A small white or yellow head, or nothing yet |
| How long it lasts | Roughly 1–3 weeks; may burst and drain | A few days to a week; deep ones longer |
The tell: Size, depth and how ill it makes you feel. A pimple is small and close to the surface. A boil is deeper, keeps growing for several days, becomes far more painful, and the skin around it turns hot and swollen. If it's still getting bigger after a few days, or you feel unwell, treat it as a boil.
Whatever it is, don’t squeeze it
Squeezing is the one thing that makes all four worse. It pushes pus and debris deeper rather than out, can spread a boil’s infection into the surrounding skin, bursts a cyst’s wall under the surface — which is what turns a quiet cyst into a painful one — and is the most common reason these bumps leave scars or dark marks, especially on darker skin.
A clean, warm, damp cloth held on for 10 to 15 minutes a few times a day is the safe way to help a pimple or boil come to a head. A boil or cyst that needs draining is drained in the office with sterile instruments and numbing — it takes minutes and heals far more cleanly than anything done at home. If it’s a pimple, the acne face map explains what drives breakouts in each area, and acne, explained covers the treatments that stop them forming.
When it keeps coming back
A bump that returns to the same spot is telling you something. A cyst that flares, settles and flares again still has its wall in place, and the only lasting fix is removing it whole. Ingrown hairs that never stop usually mean the hair removal method needs to change — laser hair removal is often the real answer. Repeated boils are worth investigating, because diabetes, a weakened immune system and carrying staph bacteria all make them more likely.
And painful, boil-like lumps that keep returning in the armpits, groin, buttocks, inner thighs or under the breasts are sometimes hidradenitis suppurativa — a long-term inflammatory condition that is often mistaken for boils, cysts or ingrown hairs for years. It isn’t caused by poor hygiene and isn’t contagious, and early treatment helps prevent the scarring and tunnels it can cause.
If it’s none of these
Plenty of lumps aren’t any of the four. Tiny, hard white bumps that never come to a head are often milia. Clusters of small itchy bumps around hair follicles are usually folliculitis. A firm cyst on the scalp is most often a pilar cyst. A soft growth hanging from a stalk is more likely a skin tag — the skin tag method picker covers those. Anything that keeps growing, bleeds without being knocked, or doesn’t heal within a few weeks should be examined.
Common questions
- How can I tell if it's a cyst or a boil?
- Ask how long it's been there. A boil appears and grows over a few days, becomes very painful, and fills with pus. A cyst is usually a painless, smooth lump that has been there for weeks or months, often with a tiny dark pore on top. An inflamed cyst can look just like a boil — but the lump was there before the pain started.
- Should I pop it?
- No — not a pimple, a boil, a cyst or an ingrown hair. Squeezing pushes the contents deeper, spreads infection, and is the most common reason these bumps scar or leave dark marks. A warm compress is the safe way to help one come to a head. Boils and cysts that need draining are drained in the office, with sterile instruments and numbing.
- Can an ingrown hair turn into a cyst?
- People often call a deep, swollen ingrown hair an “ingrown hair cyst”. Usually it's inflammation around the trapped hair rather than a true cyst with its own wall, and it settles once the hair is free. A deep ingrown hair can become infected, though. A lump that stays after the redness has gone, or keeps coming back in the same spot, is worth having checked.
- How long does a boil last?
- Most boils come to a head, drain and heal within about one to three weeks. If one hasn't improved after two weeks, keeps growing, or you develop a fever, it needs to be seen — it may need draining or antibiotics.
- Why does my cyst smell when it drains?
- Epidermoid cysts are filled with keratin and oily debris, which looks like soft cheese and has a strong odour when it comes out. The smell alone doesn't mean infection. Pain, heat and spreading redness do.
- Why do I keep getting boils?
- Many people carry the bacteria that cause boils on their skin or in their nose without knowing. Diabetes, a weakened immune system, eczema, steroid use and close contact with someone who has boils all make them more likely. Repeated boil-like lumps in the armpits, groin or buttocks can also be hidradenitis suppurativa, which is treated differently. Either way, recurring boils are worth investigating rather than enduring.
- Are boils contagious?
- The bacteria can spread, so keep a boil covered once it drains, wash your hands after touching it, don't share towels or razors, and skip the gym and the pool until it has healed. Pimples, cysts and ingrown hairs aren't contagious.
- Does a cyst need to be removed?
- Not if it's small and not bothering you. If it keeps flaring, is in an awkward place, or you'd rather it was gone, a dermatologist can remove it — ideally when it isn't inflamed, so the whole wall comes out and it doesn't grow back.
Where this comes from
Clinical descriptions on this page are drawn from these references.
- American Academy of Dermatology — How to treat boils and styes
Warm compresses, why never to squeeze or pierce a boil, how long boils take to heal, and when to see a dermatologist.
- American Academy of Dermatology — How to treat a deep, painful pimple at home
Why not to pop a deep pimple, and what to use instead.
- American Academy of Dermatology — Hidradenitis suppurativa: signs and symptoms
How early hidradenitis suppurativa resembles boils, pimples or cysts, and where it recurs.
- NHS — Boils
Self-care, what not to do, and the signs that need urgent help: a boil on the face, hot swollen skin, feeling unwell, or a weakened immune system.
- NHS — Cellulitis
Signs of a spreading skin infection, why redness is harder to see on brown and black skin, and when to go to the emergency department.
- DermNet — Epidermoid cyst
What an epidermoid cyst is, the central punctum, why cysts become inflamed, and why removal of the whole wall prevents recurrence.
- DermNet — Boils
The cause of boils and carbuncles, their usual course, and complications.
- DermNet — Pseudofolliculitis barbae
Why ingrown hairs form, who gets them, shaving technique, and how long bumps take to settle after hair removal stops.