A sebaceous cyst is a smooth, round lump under the skin that may have a small dark opening on top. A lipoma is a soft, rubbery lump of fat that moves easily under the skin. A boil is a red, hot, painful infected lump that forms quickly. Most cysts are harmless and do not need removal, but a doctor may suggest cyst removal if a cyst keeps swelling, leaking, becoming inflamed or bothers you.
This guide explains how to tell these common lumps apart, why squeezing makes things worse, and when removal makes sense. A doctor's examination is always needed for a firm answer.
Sebaceous cyst vs lipoma vs boil: what is the difference?
| Feature | Sebaceous (epidermoid) cyst | Lipoma | Boil |
|---|---|---|---|
| What it is | A closed sac under the skin filled with keratin | A slow-growing lump of fat cells | An infected hair follicle filled with pus |
| How it feels | Firm, round, smooth; moves slightly | Soft, doughy, slips under the fingers | Hot, tender, painful |
| Surface | Often a small dark pore (punctum) | Normal skin over it | Red, swollen, may form a yellow head |
| How fast it appears | Slowly, over months or years | Very slowly | Within days |
| Common areas | Face, neck, scalp, back, behind the ears | Shoulders, back, arms, neck, trunk | Neck, armpits, buttocks, thighs, face |
| Usual first step | Assessment; removal if bothersome | Assessment; may need imaging or referral | Medical treatment for infection |
A cyst can become inflamed and look like a boil, so the two are often confused. The history helps: a cyst usually existed quietly for a while before it flared.
What is a sebaceous cyst?
"Sebaceous cyst" is the everyday name for what doctors usually call an epidermoid cyst. It is a small sac of skin cells under the surface, filled with a soft, cheesy material called keratin. If it leaks, it can smell unpleasant.
Cysts are common on the face, neck, scalp and back. Many stay small and quiet for years. Others swell from time to time, especially if they are squeezed, rubbed or become infected. They are benign, which means they are not cancer.
What is a lipoma?
A lipoma is a lump of fat cells under the skin. It feels soft and rubbery and usually moves easily when pressed. It usually causes no pain and grows very slowly. Lipomas are also benign.
Lipomas are handled differently from cysts. Depending on the size, depth and location, the doctor may advise leaving it alone, arranging a scan, or referring you to a surgeon. Please do not assume every soft lump is a lipoma. A lump that is hard, fixed, painful or growing quickly needs prompt medical assessment.
What is a boil?
A boil is a bacterial infection of a hair follicle. It starts as a tender red bump and fills with pus over a few days. Boils are more common in hot, humid weather, with friction from tight clothing, and in people with diabetes. Delhi summers and the monsoon are a common time for them.
A boil is not removed like a cyst. It needs treatment for the infection, and sometimes drainage by a doctor. Seek medical care quickly if you have a fever, spreading redness, a boil on the face near the nose or eyes, repeated boils, or diabetes.
Other common bumps: milia and molluscum
Two other bumps are often mistaken for cysts:
- Milia are tiny, hard white bumps, usually around the eyes and cheeks. They are harmless and can be released by a doctor through a tiny opening.
- Molluscum contagiosum causes small, pearly, dome-shaped bumps with a dimple in the centre. It is caused by a virus and spreads by skin contact. It may be treated with gentle removal, freezing or cautery.
Skin tags and moles can also be confused with small cysts. These are assessed and treated differently; see mole and skin tag removal.
Deep, painful lumps on the face, chest or back that come and go with breakouts may be cystic acne rather than true cysts. These need a medical acne plan. See our page on acne breakouts.
When should a cyst be removed?
Not every cyst needs removing. A doctor may suggest removal when a cyst:
- Keeps swelling, becoming inflamed or getting infected
- Leaks or smells
- Catches on clothing, combs, collars or straps
- Is growing, or is in a visible area that bothers you
The aim is to remove the whole sac, which lowers the chance of the cyst coming back. Cysts can still occasionally return.
Why can't an inflamed cyst be removed the same day?
If a cyst is red, hot and painful, it is usually treated with medicines first, and sometimes drained. Removal is planned once the inflammation settles. An inflamed sac is fragile and harder to remove in one piece. Waiting usually gives a cleaner result and a lower chance of return.
Why you should not squeeze a cyst
Squeezing a cyst at home rarely empties it fully. The sac stays behind and refills. Pressure can also burst the sac under the skin, causing painful inflammation, infection and a larger scar. Needles and blades at home add a real risk of infection. Please leave it for a doctor.
What does cyst removal involve, and how long is recovery?
Cyst removal is a minor procedure performed by a qualified doctor under local anaesthesia, after assessment. You stay awake but comfortable. The area is numbed, a small cut is made, and the sac is removed. Small cuts may be closed with a few stitches. The procedure usually takes 15 to 45 minutes.
Most people go home soon after. Expect mild pain, swelling or bruising for a few days. Avoid heavy exercise and sweating if you have stitches, and return on time for review or stitch removal. Any cut leaves a small scar, which usually fades and flattens over months. Temporary dark marks are more common on darker skin, so use sunscreen once healed. Results vary from person to person. More details are on our cyst and milia removal in Delhi page.
Tell the doctor first if you are pregnant or breastfeeding, take blood thinners, have a history of keloids, or have diabetes, weak immunity or slow wound healing.
After removal, contact the clinic if you notice increasing pain, redness, warmth or pus, bleeding that soaks the dressing, a fever, or stitches coming apart.
Frequently asked questions
Can a sebaceous cyst go away on its own?
A cyst can shrink after it drains, but the sac usually remains and the cyst often refills over time. Small, quiet cysts can be left alone if they do not bother you. If a cyst keeps flaring up, leaking or growing, removal of the whole sac is the more lasting option. A doctor can advise on timing.
Is a lump under the skin a sign of cancer?
Most lumps under the skin, such as cysts and lipomas, are benign. Still, any new lump should be checked. See a doctor promptly if a lump is hard, fixed in place, growing quickly, painful without a clear reason, or comes with weight loss or fever. The doctor may advise tests or a referral rather than removal.
Do you remove lipomas?
Lipomas are assessed at consultation. Depending on their size, depth and location, the doctor may advise leaving them, arranging a scan, or referring you to a surgeon. Our cyst removal service focuses on cysts, milia and molluscum. The doctor will tell you plainly where a lipoma should be treated.
Will cyst removal leave a scar?
Yes, any cut leaves a scar, though it is usually small and fades over months. The doctor plans the cut to keep it as neat as possible. People prone to keloids should mention this first. Keeping the wound clean, not stretching it early and using sunscreen once healed all help.
Can a cyst come back after removal?
Removing the whole sac lowers the chance of return, but cysts can occasionally come back. An inflamed cyst is harder to remove fully, which is why it is usually calmed first. If you notice a lump returning in the same place, book a review.
Should I put a hot compress on a boil?
A warm compress can ease discomfort and help a small boil drain on its own. Do not squeeze or pierce it. See a doctor if it is large, very painful, on the face, keeps coming back, or if you have a fever or diabetes. These need medical treatment rather than home care.
If you have a lump you are unsure about, a doctor can examine it and explain whether it needs removal, treatment or simply watching. Book a free consultation at any of our four clinics in Vasant Vihar, Gurugram, Pitampura or Civil Lines.
