Anesthesia is broken down into three main categories: local, regional, and general, all of which affect the nervous system in some way and can be administered using various methods and different medications.
Here's a basic look at each kind:
Local anesthesia. An anesthetic drug (which can be given as a shot, spray, or ointment) numbs only a small, specific area of the body (for example, a foot, hand, or patch of skin). With local anesthesia, a person is awake or sedated, depending on what is needed. Local anesthesia lasts for a short period of time and is often used for minor outpatient procedures (when patients come in for surgery and can go home that same day). For someone having outpatient surgery in a clinic or doctor's office (such as the dentist or dermatologist), this is probably the type of anesthetic used. The medicine used can numb the area during the procedure and for a short time afterwards to help control post-surgery discomfort.
Regional anesthesia. An anesthetic drug is injected near a cluster of nerves, numbing a larger area of the body (such as below the waist, like epidurals given to women in labor). Regional anesthesia is generally used to make a person more comfortable during and after the surgical procedure. Regional and general anesthesia are often combined.
General anesthesia. The goal is to make and keep a person completely unconscious (or "asleep") during the operation, with no awareness or memory of the surgery. General anesthesia can be given through an IV (which requires sticking a needle into a vein, usually in the arm) or by inhaling gases or vapors by breathing into a mask or tube.
The anesthesiologist will be there before, during, and after the operation to monitor the anesthetic and ensure you constantly receive the right dose. With general anesthesia, the anesthesiologist uses a combination of various medications to do things like:
keep you asleep
minimize pain during surgery and relieve pain afterward (using drugs called analgesics)
To better understand how the different types of anesthesia work, it may help to learn a little about the nervous system. If you think of the brain as a central computer that controls all the functions of your body, then the nervous system is like a network that relays messages back and forth from it to different parts of the body. It does this via the spinal cord, which runs from the brain down through the backbone and contains threadlike nerves that branch out to every organ and body part.
Will I Get a Needle?
Often, anesthesiologists may give a person a sedative to help them feel sleepy or relaxed before a procedure. Then, people who are getting general anesthesia may get medication through a breathing mask first and then be given an IV after they're asleep. Why? Many people are afraid of needles and may have a hard time staying still and calm, so doctors may need to help them relax first with this medicine.
What Type of Anesthesia Will I Get?
The type and amount of anesthesia given to you will be specifically tailored to your needs and will depend on various factors, including:
the type of surgery
the location of the surgery
how long the surgery may take
your current and previous medical condition
allergies you may have
previous reactions to anesthesia (in you or family members)
medications you are taking
your age, height, and weight
The anesthesiologist can discuss the options available, and he or she will make the decision based on your individual needs and best interests.