Cauterization is the application of heat , mechanically or chemically, to prevent or stop bleeding. It is widely used in surgery to hold bleeding to a minimum and speed the surgical process.
Searing areas of bleeding with a hot instrument, a hot iron or other metallic object, was practiced for many years for the treatment of wounded soldiers. Even thousands of years ago, all wounded were treated by pouring boiling oil into the wound to arrest bleeding. Of course, in this case the cure was nearly as harmful as the original injury. Many of the wounded, already in shock from their trauma, were plunged into deeper shock and death by the oil.
As surgery progressed and anesthesia was introduced to quiet the patient and prevent his feeling pain , more care and more time could be devoted to preventing bleeding. In making an incision the surgeon would cut across small blood vessels such as capillaries and arterioles that would begin to ooze blood. The surgeon then had to locate each point of bleeding and apply a clamp to stop it, and then go back and tie a suture around each bleeder, a long and exacting process.
The electric cautery, a form of scalpel, then was invented and introduced into the surgical suite. Using this instrument the surgeon could make his incision and the cautery seared and sealed off all sites of bleeding except the largest ones. This considerably reduced the time the surgeon spent in stanching the flow of blood into the surgical field. It was also a benefit to the patient who spent less time under the anesthetic and reduced the amount of blood loss.
Currently the ubiquitous laser has been introduced as a scalpel. The powerful beam cuts into tissue and opens the incision while at the same time heat-searing the small blood vessels.
Chemical cauterization also is used in limited circumstances. For example, one means of stopping a nosebleed that has defied all other means of cure is to use an applicator with silver nitrate on one end. The silver nitrate is applied directly to the bleeding area and cauterizes it.
See also Laser surgery.