Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical purposes.
If you are having surgery, your doctor will give you medicine called an anesthetic. Anesthetics reduce or prevent pain. Anesthesia enables the painless performance of medical procedure that would otherwise cause severe or intolerable pain to an unanesthetized patient, or would otherwise be technically unfeasible.
All types of anesthesia are administered to keep you comfortable and pain-free during surgery, medical procedures or tests. But there are some key differences. The type you receive will depend on factors like the procedure, your health and your preference.
There are four types of anesthesia that are used during any medical procedure:
General AnesthesiaGeneral anesthesia is used for major operations, such as a knee replacement or open-heart surgery, and causes you to lose consciousness.
IV/Monitored SedationSedation is often used for minimally invasive procedures like colonoscopies. The level of sedation ranges from minimal — drowsy but able to talk — to deep.
Regional AnesthesiaRegional anesthesia is often used during childbirth and surgeries of the arm, leg or abdomen. It numbs a large part of the body, but you remain aware.
Local AnesthesiaLocal anesthesia is for procedures such as getting stitches or having a mole removed. It numbs a small area, and you are alert and awake.
Source: American Society of Anesthesiologists