Cryosurgery (also called cryotherapy) is the process of destroying diseased skin cells (lesions) by freezing them with liquid nitrogen. It may be used to treat conditions such as warts.
For cryotherapy, the skin may first be numbed with a local anesthetic. The liquid nitrogen is applied or sprayed onto the lesion and the immediate surrounding tissue. The application may be repeated.
WebMD Medical Reference from Healthwise