Patient guide
Cryotherapy: freezing skin growths with liquid nitrogen
By the SkinOps team · Updated · 2 min read
Based on information from the NHS website. This guide is waiting for review by a clinician and is not medical advice.
Cryotherapy is a treatment that freezes skin growths with liquid nitrogen. It is quick, usually needs no anaesthetic, and is commonly used on warts, verrucas and sun-damaged patches of skin.
It does not work instantly. Most growths need one or more follow-up treatments, and the area often blisters before the growth falls off.
What cryotherapy is used for
A GP or nurse may suggest cryotherapy for:
- warts and verrucas that have not cleared up on their own
- skin tags
- actinic keratoses, dry scaly patches caused by sun damage
Actinic keratoses are treated because they carry a small chance of turning into skin cancer over time. Warts, verrucas and skin tags are frozen mainly because they are unwanted or uncomfortable, not because they are dangerous.
What happens during treatment
Liquid nitrogen is applied directly to the growth, often with a spray or a cotton bud, for a few seconds. It stings or burns briefly. Because the freeze is so short, a local anaesthetic is not usually needed.
More than one growth can often be treated in the same visit, and warts sometimes need repeat sessions a few weeks apart before they clear.
What to expect afterwards
- redness and swelling in the treated area for a couple of days
- a blister may form, which usually settles as a scab within a few days
- the growth typically falls off or fades over the following weeks, not immediately
Do not pick at the area
Let any blister or scab heal on its own. Picking at it increases the chance of infection or scarring.
When to see a GP
Go back to your GP if a treated patch does not improve, gets bigger, changes colour, becomes painful, or if you notice a new growth. For actinic keratoses, report any patch that bleeds, thickens or develops a lump, as this needs a proper look.
NHS or private?
The NHS treats actinic keratoses because of the small skin cancer risk, and a GP will treat warts or verrucas that are causing problems. Freezing a skin tag or wart purely for cosmetic reasons is not usually funded, so this is typically done privately.