Skip to Content

Anesthesia

Surgeon using anesthesia on patient

What is anesthesia?

Anesthesia is the practice of administering medicines that block the feeling of pain and other sensations to allow medical or surgical operations to take place without causing undue distress or discomfort. There are various types of anesthesia, and most are given by inhalation (breathing in through the nose and mouth) or injection. Medications used to induce anesthesia are called anesthetics.

    Anesthesia is usually administered before an operation by an anesthesiologist or anesthetist. How anesthesia works is still only partially understood.

    What happens during anesthesia?

    Not all anesthesia causes you to lose consciousness.

    The main types of anesthesia are:

    • Procedural sedation: Commonly used outside of an operating room setting, procedural sedation provides a depressed level of consciousness so that a patient can tolerate unpleasant procedures without affecting cardiovascular function and without the need for airway management (help with breathing)
    • Conscious sedation: Conscious sedation reduces a patient's level of consciousness to a certain extent while still maintaining a certain level of awareness so that they can respond purposefully to verbal commands or light stimulation by touch. The term is often misused to describe other levels of sedation
    • Analgesia: Uses medications that act locally (which means in a small defined area) to reduce or eliminate pain in that area
    • Regional anesthesia: involves an injection of a local anesthetic in the vicinity of a major nerve bundle that supplies a particular body area, for example, epidurals (into the spine) for childbirth, nerve blocks for dental procedures. May be used on its own or combined with general anesthesia. Typically results in numbness or tingling in an area supplied by the nerves and moving that region of the body may become difficult or impossible
    • General anesthesia: Uses a combination of intravenous and inhaled gases to produce a sleep-like state where the patient is unconscious and will not respond to any stimuli, including pain. This may cause changes in breathing and circulation which will need to be monitored. Rarely, some people may experience unintended intraoperative awareness

    What are the side effects of anesthesia?

    In most circumstances, anesthesia is very safe; even people who are quite seriously ill can be safely anesthetized. It is often the surgery that carries the biggest risk.

    Side effects of local anesthesia may include:

    • Pain around the injection site
    • Prolonged numbness that takes a few hours to wear off
    • Dribbling or difficulty speaking if anesthesia was in the mouth

    Side effects of general anesthesia include:

    • Bruising or soreness from the IV drip
    • Dizziness
    • Feeling cold, shivering
    • Nausea and vomiting
    • Sore throat (from the breathing tube)
    • Temporary memory loss and confusion

    Complications after anesthesia may include an increased risk of a heart attack, pneumonia, or stroke.