What is a skin cyst?
A skin cyst is a closed sac beneath the skin filled with keratin (skin cell debris) — most commonly an epidermoid cyst, sometimes loosely called a "sebaceous cyst" even though true sebaceous (oil gland) cysts are less common. They form a smooth, round, movable lump under the skin, often with a small central pore (punctum) visible on the surface.
Cysts are always benign and grow slowly over months to years. Many people choose to leave small, asymptomatic cysts alone; others prefer them removed, particularly if they're in a visible location, keep growing, or have become inflamed or infected in the past.
What causes them
- A blocked hair follicle or oil gland, trapping keratin beneath the skin.
- Previous skin trauma or acne in the area.
- They're more common with age and can run in families.
When to get it checked
- Most cysts are straightforward to recognise: a smooth, mobile, round lump, sometimes with a visible central punctum.
- A cyst that becomes red, tender, warm, or starts discharging suggests infection or inflammation and should be assessed.
- Any lump that's growing quickly, feels unusually firm or fixed to the skin, or doesn't fit the typical picture is worth a proper look rather than assuming it's "just a cyst."
Diagnosis
Most cysts are diagnosed on clinical examination alone. If there's any uncertainty about the diagnosis, or the lump has atypical features, we may recommend removal with the tissue sent for histopathology to confirm.
Removal options
Surgical excision
The cyst and its wall are removed under local anaesthetic — the most reliable way to prevent recurrence.
Incision & drainage
For an acutely inflamed or infected cyst, drainage may be needed first, with definitive removal once settled.
Antibiotics
If a cyst is infected, a course of antibiotics may be recommended alongside or before removal.
Watchful waiting
Small, stable, asymptomatic cysts can reasonably be left alone if they aren't bothering you.
Good to know
- Cysts can't really be prevented, but avoiding squeezing or attempting to pop them at home reduces the risk of infection and scarring.
- If a cyst has become infected before, it's more likely to recur in the same spot — full surgical removal (including the cyst wall) is the best way to prevent this.
Frequently asked questions
Can I pop a cyst myself?
We'd recommend against it. Squeezing a cyst rarely removes it completely — the wall is usually left behind, so it tends to refill — and it significantly raises the risk of infection and scarring. In-clinic removal deals with the whole cyst properly.
Is Medicare rebate available for cyst removal?
Removal for a medical reason, such as a cyst that's infected, painful, or repeatedly inflamed, is generally Medicare-rebatable. Purely cosmetic removal of an asymptomatic cyst may not be — check our Fees page or ask reception for current details.
Will a cyst come back after removal?
If the entire cyst wall is removed surgically, recurrence in that exact spot is uncommon. Incision and drainage alone (without removing the wall) has a higher chance of the cyst reforming.