What Is Liquid Nitrogen Used For?

A clinician applies liquid nitrogen to a targeted area with a spray or a small applicator. The intense cold damages the unwanted surface tissue, which then forms a crust or blister and separates as the skin heals. Cryotherapy may be considered for some warts, actinic keratoses, seborrhoeic keratoses, and other lesions after an examination. Not every changing or uncertain lesion should be frozen; a clinician may need to assess it more closely first.

The treated spot can sting or burn briefly. Redness, swelling, blistering, tenderness, and temporary lightening or darkening of the skin can follow. Healing depends on the lesion, location, and depth of freezing. See [Liquid Nitrogen](/materials/liquid-nitrogen/) and [Cryotherapy (Lesion Removal)](/treatments/surgical-dermatology/cryotherapy-lesion-removal/) for related information.

Keep the area clean and follow the clinic's dressing instructions. Do not deliberately break a blister or pull away a crust. Protect healing skin from friction and sunlight, and use only products recommended for the site. Tell the clinician about immune problems, poor wound healing, diabetes, circulation concerns, or medicines that affect bleeding before treatment. Attend review if the lesion does not heal as expected or if further treatment is suggested.

Ask for medical advice if pain is worsening, redness spreads beyond the treated area, pus develops, the site becomes increasingly warm, or you develop a fever. Seek urgent help for heavy bleeding, rapidly increasing swelling, or signs of a serious allergic reaction. A sore that fails to heal or a lesion that changes after treatment also needs clinical review.

Ask what the lesion is thought to be, why freezing is suitable, how the site should be dressed, and what colour or texture change may remain. Clarify whether a sample is needed before treatment and when the area should be checked again.