Medical uses of liquid nitrogen include cryosurgery, which is the removing of skin growths such as warts and precancerous growths such as actinic keratoses, according to the Permanente Medical Group. Doctors also use the chemical to treat cancers that surgeons cannot remove, such as a retinoblastoma in the eye.
Doctors may use a spray container or a cotton swab when applying liquid nitrogen to skin growths, explains the Permanente Medical Group. At about minus 328 F, liquid nitrogen is very cold, and it freezes a growth and surrounding tissue instantly. Patients typically experience stinging or burning during the process, and swelling and blistering about three to six hours afterward, which is normal. The blister flattens approximately three days after the procedure; within three weeks, it falls off.