Cryotherapy is usually used for skin cancer and only if it is affecting the surface layers of your skin.
Liquid nitrogen is sprayed on to the cancer to freeze it. The cold can be a bit painful when the liquid nitrogen is applied (some patients describe the feeling as like a bee-sting).
After the treatment you may feel a burn-like sensation in the area. Within a day or so the area may blister. The blister may contain blood. Fluid may need to be drained from the blister using a sterile needle, but the top of the blister should be left intact.
The treated area needs to be covered with a dressing until a scab forms. About a month after the treatment, the scab drops off and the cancer cells should have cleared. You may have a white scar in the area. Occasionally, more than one cryotherapy treatment is needed to get rid of the tumour completely.