If you are having surgery, your doctor will give you a drug called an anesthetic. Anesthetics reduce or prevent pain. There are four main types.

• Local: numbs one small area of the body. You stay awake and alert.
• Conscious or intravenous (IV) sedation: uses a mild sedative to relax you and pain medicine to relieve pain. You stay awake but may not remember the procedure afterwards.
• Regional anesthesia: blocks pain in an area of the body, such an arm or leg. Epidural anesthesia, which is sometimes used during childbirth, is a type of regional anesthesia.
• General anesthesia: affects your whole body. You go to sleep and feel nothing. You have no memory of the procedure afterwards.

The type of anesthesia your doctor chooses depends on many factors. These include the procedure you are having and your current health.

Types of anesthesia

Anesthesia can be categorized by the degree to which it suppresses consciousness and protective reflexes. Larger procedures often require greater amounts of anesthesia. From least to most, levels of anesthesia include: local, conscious sedation, regional and general. Determining the best choice for you depends on the anticipated nature and duration of the procedure, as well as your medical and psychological health. Discuss your options with your doctor.

Local anesthesia
Local anesthesia is used to block pain in a specific part of your body, allowing you to remain fully alert. The area that is anesthetized is usually small and superficial. Typically, a local anesthetic is used for dental work, skin biopsies or stitching up a cut. Sometimes a local anesthetic is used for a more extensive procedure in people for whom general or regional anesthesia is inadvisable.

For local anesthesia, an anesthetic is injected at or near the site of the procedure. The injection numbs the area to pain and any other sensation. Local anesthetics are generally of short duration. They come in different forms, including injections, sprays and ointments. Only rarely do they cause an allergic reaction.

Conscious sedation
Conscious sedation or intravenous (IV) sedation is used to relax you and make you feel sleepy. It generally includes intravenous administration of pain medication and a mild sedative to minimize any discomfort. These medications also cause temporary forgetfulness, so you may not remember what happens during the procedure.

Even though you may not remember anything that occurs during conscious sedation, you remain awake enough during that time to respond to questions and retain your protective reflexes. For example, if secretions accumulated in your throat, you would swallow or cough. This type of anesthesia is used for procedures such as colonoscopy, an exam of your colon and rectum. Conscious sedation is also frequently combined with regional anesthesia.

Regional anesthesia
Regional anesthesia is used to block sensation in a particular region of your body, such as the lower half of your body, an eye, or an arm or leg. As with local anesthesia, you remain conscious during regional anesthesia. Often regional anesthesia is combined with conscious sedation, so you might not remember any of the procedure.

The anesthetic is injected around a single nerve or a network of nerves that serve the area involved in the surgical procedure. You receive the injection, which is generally painless, while lying on your back or side, or sitting.

To eliminate pain in the lower half of your body, spinal, epidural or caudal anesthetics may be injected near your spinal cord. These forms of anesthesia are often used for pelvic operations and for leg and hip surgery. Epidural anesthesia is often used during childbirth.

The main advantage of regional anesthesia is that it provides a high level of anesthesia to a selected region of the body while having little effect on other areas, such as your heart, lungs and brain. In regional anesthesia, your protective reflexes remain intact.

An additional benefit of regional anesthesia is that it helps control postoperative pain. That means you may require less pain medication after surgery and can avoid the nausea and grogginess that often result from those medications.

General anesthesia
General anesthesia is used for more extensive procedures or for procedures that aren't amenable to regional anesthesia. The medications used in general anesthesia are given intravenously or by inhalation. The drugs circulate in your bloodstream to all areas of your body, including your brain. They can suppress all of your protective reflexes, such as coughing, gagging and even breathing. Consequently, a general anesthetic requires the use of a mask or breathing tube while you're asleep.

Because general anesthetics affect all areas of your body, such as the heart and lungs, side effects from the medications are more common. However, most are temporary and can be managed by your medical team.