Approved by the Cancer.Net Editorial Board, 10/2018

Listen to the Cancer.Net Podcast: Anesthesia - What to Expect, adapted from this content

Anesthesia is medicine that blocks the awareness of pain. It is used during certain medical procedures. The type depends on the procedure and your overall health.

Types of anesthesia

There are 4 main types:

Local anesthesia. Local anesthesia is an injection that numbs the procedure site. It is typically used for small procedures. Examples include a breast biopsy or a mole removal. The numbing lasts for a short time, potentially several hours. You might remain awake and alert. Or your doctor may use sedation to make you relaxed and sleepy. (See “Sedation” below.)

Regional anesthesia. Regional anesthesia blocks pain in 1 part of the body. The injection provides pain relief during and after surgery. This makes recovery easier.

There are 2 common types of regional anesthesia:

  • Peripheral nerve block anesthesia prevents sensation in the limbs. For example, limbs include arms, hands, legs, or feet.

  • Epidural and spinal anesthesia prevents midsection and lower-body pain. These areas include the abdomen, pelvis, rectum, and lower limbs.

Sedation. Sedation uses medication to make you relaxed and sleepy. You may receive it by mouth as a liquid or pill. Or you may receive the medication through a vein. This is called intravenous (IV) medication. Sedation may be used with local or regional anesthesia to reduce pain.

The levels of sedation are based on how aware and awake you are:

  • Minimal sedation makes you relaxed and reduces anxiety. You remain awake, and you can speak during the procedure. Typically, this type is used for uncomfortable tests or procedures, such as a colonoscopy.

  • Moderate sedation is also called conscious sedation. It reduces pain and lowers your awareness. Some people under conscious sedation can still speak and respond. Others fall into a light sleep. It is often used for minor surgeries. You may not remember the procedure afterwards.

  • Deep sedation makes you unaware of the procedure. Usually, you cannot speak or answer questions. You can respond to pain, but pain medication reduces discomfort. You may also receive drugs that affect your memory. This means you will not remember the procedure afterwards. You may also receive assistance breathing.

General anesthesia. General anesthesia uses a combination of drugs. This makes you unconscious during a major procedure, like surgery. Being unconscious is different from sleeping. You cannot wake up until the anesthesia wears off or until you receive medication to help you wake up.

Who gives anesthesia?

The anesthesia care team typically includes the following professionals:

An anesthesiologist. This doctor specializes in giving anesthesia and related care. He or she will lead your anesthesia care team.

Certified registered nurse anesthetists, also called CRNAs. These registered nurses are trained in anesthesia.

Anesthesia assistants, also called AAs. These health care professionals have undergone graduate-level training. They specialize in anesthesia care and advanced patient-monitoring techniques.

Getting ready for anesthesia

Evaluations. Before receiving general anesthesia, you may meet with the anesthesiologist. And you will receive a questionnaire. The discussion may include the following topics:

  • Your health history

  • Prescription and over-the-counter medicines, vitamins, and herbal supplements you take

  • Allergies, including food, medication, and substances such as latex

  • Previous experiences with anesthesia

  • Drug, alcohol, and tobacco use

It is important to answer these questions accurately and honestly.

You may also need blood tests or other examinations beforehand. The information helps identify the safest type of anesthesia for you. For example, if you have neck pain or a history of arthritis of the neck and will receive general anesthesia, you may need an x-ray. This is because your neck may be moved while giving anesthesia.

Restrictions. You will learn about food, drink, and medicine restrictions. Typically, you should fast for about 6 hours before the procedure. You should not eat or drink anything other than clear liquids. And you may need to temporarily stop taking current medications. Some medications could interfere with the anesthesia or the procedure. But do not stop taking medication without first asking your doctor. Tell your doctor if you have any loose teeth or dental bridges as some type of anesthesia may involve movement of your mouth.

What happens during general anesthesia?

You will receive general anesthesia in 1 of these ways:

  • Through an IV line inserted in a vein in your arm

  • Through a face mask or tube in the larynx that helps you inhale the medicine

  • Through a combination of both

Most likely, you will become unconscious in less than 1 minute.

Beforehand, your health care team will attach monitoring devices to your body. These devices track your vital signs. Vital signs include temperature, blood pressure, and heart rate.

During the procedure, the health care team will make sure that vital signs stay at appropriate levels. They will also monitor your level of consciousness.

The anesthesiologist may choose to give additional medicine for these reasons:

  • To increase the strength of the anesthesia

  • To provide additional pain relief

  • To further relax the muscles to help the surgeon complete the procedure

  • To reduce the risk of side effects after the procedure

After the procedure ends, the anesthesiologist will gradually stop the anesthesia. And you may receive other medications to help you wake up.

Specially trained nurses will monitor you as you regain consciousness. This typically takes place in a recovery room or a post-anesthesia care unit.

Potential side effects of anesthesia

Side effects may include:

  • Grogginess, sleepiness, or confusion

  • Nausea or vomiting

  • Chills

  • Dry mouth or sore throat. This may occur if a tube went through your mouth and airway. Sometimes, a tube helps you breathe during the procedure.

These side effects are temporary. And the health care team will help you manage them.

Rare complications of anesthesia include serious injury and death. These risks are often higher for older adults, especially people who have severe heart or lung disease.

Another rare complication is anesthesia awareness. This means a person briefly wakes up during the procedure. It occurs in 1 or 2 out of every 1,000 people.

Risk factors for anesthesia awareness are:

  • Emergency surgery

  • A long history of anticonvulsant, opiate, or tranquilizer use

  • Cardiovascular problems

  • Daily alcohol use

  • A history of smoking

For most people, anesthesia causes no harm.

Recovering from anesthesia

Avoid these activities for at least 24 hours after waking up:

  • Driving a car

  • Operating heavy machinery

  • Making important decisions

Your reaction speed and judgment may be temporarily impaired by the anesthesia.

If your recovery is not going well, contact your health care team right away.

Ask your health care team when to restart regular medicines. And ask about temporary restrictions on eating and drinking. You may have trouble digesting heavy foods. You may start with liquids, followed by light foods.

Examples of light foods include:

  • Broth or soup

  • Tea or black coffee

  • Yogurt

  • Gelatin

  • Toast, crackers, or plain rice

Questions to ask your health care team

Before receiving anesthesia, you may want to ask these questions:

  • Do I have a choice about the type of anesthesia I receive?

  • What are the risks and complications with each type of anesthesia?

  • How can I prevent or lower risks and complications?

  • Do I need any tests before receiving anesthesia?

  • May my family come with me to the operating room?

  • Can I bring any electronic devices and headphones to the operating room?

  • What care will I receive before, during, and after my procedure?

Related Resources

What is Cancer Surgery?

What to Expect When Having Surgery

Side Effects of Surgery

More Information

American Society of Anesthesiologists: Anesthesia 101

MedlinePlus: Anesthesia