Types of Anesthesia Used During Surgery

Anesthetist administering gas to patient
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Anesthesia is the administration of medication to allow medical procedures to be done without pain and, in some cases, without the patient being awake during the procedure. It is used in a wide range of procedures, from highly invasive surgeries, such as open-heart surgery, to minor procedures such as having a tooth extracted.

There are four types of anesthesia: general, regional, local, and monitored anesthesia care (MAC). Several different medical professionals are able to administer these for a variety of purposes.

The type of anesthesia used typically depends on the type of surgery, your state of health, the length of the procedure, and the preferences of your anesthesia provider and surgeon.

General Anesthesia

With general anesthesia, you are typically given a combination of medications through a mask or IV. This will render you temporarily unconscious.

General anesthesia also paralyzes your muscles, including those that make it possible to breathe. For this reason, you will require a ventilator to do the work of the diaphragm and other muscles that help make it possible to inhale and exhale. Your anesthesia provider will continuously monitor your vital signs, such as heart rate, blood pressure, and breathing, during your procedure.

When the surgery is done, other medications are used to reverse the effect of the anesthesia. You will also be monitored in this recovery phase.

This is the strongest type of anesthesia and is most commonly used for surgeries that would otherwise be unbearably painful, such as knee replacements and heart surgeries. It may also be used in certain circumstances where a patient's cooperation during the procedure cannot be guaranteed, such as when a child needs a myringotomy (ear tubes).

Regional Anesthesia

Regional anesthesia is provided by injecting specific sites with a numbing medication. This may be done with a needle or via a flexible catheter line through which anesthetics and other medications can be administered as needed.

With this type of anesthesia, only the body part being operated on is numbed, which means you are awake—that is, sedated, but still conscious—during the procedure. The anesthetic works on the nerves, causing numbness below the injection site. You are monitored throughout your procedure.

Epidurals (spinal blocks), in which medication is administered in your back, are an example of regional anesthesia. Medication is delivered to cerebrospinal fluid through a fine needle to the spinal sac. Epidurals provide continuous pain relief as long as medications are continuously running and there are no side effects.

Spinal blocks have different uses, including to block sensation in your arms and legs during surgeries on your limbs. They are also commonly given during childbirth (at a patient's request) to restrict pain medication to one area of the body in an effort to prevent a fetus from being exposed to sedatives that may be harmful to them.

Another example of regional anesthesia is a peripheral nerve block, which may be given in the shoulder/arm, back, or leg regions. If you are having hand surgery, your anesthesia provider may use a peripheral nerve block to numb your entire arm and hand, or the numbness may be mostly limited to your hand.

Local Anesthesia

This type of anesthesia is typically used to numb a small site for minor procedures, such as filling a cavity or for a skin biopsy. During the administration of local anesthesia, a numbing medication is either applied to the skin as a cream or spray, or injected into the area where the procedure will be performed.

If the medication is injected, several small injections are sometimes used. A few minutes after this is complete, the area should be completely numb. If the area still has sensation, additional injections or applications may be given to ensure total numbness.

Monitored Anesthesia Care (MAC)

This is a type of sedation commonly referred to as "twilight sleep." It's usually used for outpatient procedures such as a colonoscopy or cataract surgery, and is administered through an IV to make you feel sleepy and relaxed.

While you may be heavily sedated, this type of anesthesia is different from general anesthesia because you are not chemically paralyzed, nor do you require assistance with breathing. Still, your vital signs are closely monitored to make sure you are stable throughout the procedure.

This type of anesthesia wears off in as little as 10 minutes. Depending on the medications used and the doses given, you may or may not remember the procedure.


Just as no surgery is risk-free, no type of anesthesia is 100% safe either. However, generally speaking, risks increase as the level of anesthesia increases.

The main side effects of MAC are:

  • Nausea
  • Vomiting

Side effects of local anesthesia can include:

  • Soreness where the anesthetic was injected
  • Allergic reaction to the anesthetic

Regional anesthesia risks include:

  • Allergic reaction to the anesthesia used
  • Bleeding around the spinal column
  • Difficulty urinating
  • Drop in blood pressure
  • Infection in your spine
  • Nerve damage
  • Seizures
  • Severe headache

Some of these side effects, such as nerve damage and seizures, are rare, but always talk to your doctor if you have concerns.

General anesthesia can also involve minor side effects like nausea, vomiting, confusion, and sore throat, as well as the following rare, but serious risks:

  • Postoperative cognitive dysfunction: Often referred to as "brain fog," this can lead to long-term memory and learning problems.
  • Malignant hyperthermia: This is a serious reaction to anesthesia that can occur during surgery, causing a quick fever, muscle contractions, and even death. If you or a family member has ever experienced this condition during surgery or have ever had heatstroke, you're at a higher risk, so it's very important to talk to your doctor about this.
  • Breathing problems during or after surgery: General anesthesia can cause the throat to close up during surgery, which can make it more difficult to regain consciousness and begin to breathe normally after your procedure. This potential is of particular concern if you suffer from obstructive sleep apnea.

Who Provides Anesthesia?

There are several types of medical professionals who are able to provide anesthesia, including physicians (anesthesiologists), nurse anesthetists, dentists/oral surgeons, and anesthesiologist assistants. The level of training varies between different types of providers, with anesthesiologists having the highest level.

Preparing for Anesthesia

Getting anesthesia may or may not be something that is a choice in your case, as some procedures simply cannot be done without it. Whether you are preparing for a procedure with anesthesia or considering whether or not you should get it, speak with your doctor to get answers to some key questions, including:

  • Should eat or drink anything before the procedure?
  • How you might feel coming out of anesthesia?
  • How long you might need to stay at the hospital (if applicable)?
  • Should you plan for someone to take you home afterward?

In that or another pre-procedure conversation, also be sure to completely answer any questions your provider has about your general health, allergies, medications, personal and family medical history, previous surgeries and reactions to anesthesia, and so on. Doing so can help ensure that certain risks are avoided or, if necessary and possible, another form of anesthesia is considered.

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Article Sources
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