General anesthesia is the use of medicines to make a person "go to sleep" (unconscious) for a medical procedure. General anesthesia must be used for certain procedures, and is often recommended for procedures that:

  • Last a long time.
  • Require you to be still or in an unusual position.
  • Are major and can cause blood loss.

The medicines used for general anesthesia are called general anesthetics. As well as making you unconscious for a certain amount of time, these medicines:

  • Prevent pain.
  • Control your blood pressure.
  • Relax your muscles.

Tell a health care provider about:

  • Any allergies you have
  • All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
  • Any problems you or family members have had with anesthetic medicines.
  • Types of anesthetics you have had in the past.
  • Any blood disorders you have.
  • Any surgeries you have had.
  • Any medical conditions you have.
  • Any recent upper respiratory, chest, or ear infections.
  • Any history of:
    • Heart or lung conditions, such as heart failure, sleep apnea, asthma, or chronic obstructive pulmonary disease (COPD).
    • Military service.
    • Depression or anxiety.
  • Any tobacco or drug use, including marijuana or alcohol use.
  • Whether you are pregnant or may be pregnant.

What are the risks?

Generally, this is a safe procedure. However, problems may occur, including:

  • Allergic reaction.
  • Lung and heart problems.
  • Inhaling food or liquid from the stomach into the lungs (aspiration).
  • Nerve injury.
  • Dental injury.
  • Air in the bloodstream, which can lead to stroke.
  • Extreme agitation or confusion (delirium) when you wake up from the anesthetic.
  • Waking up during your procedure and being unable to move. This is rare.

These problems are more likely to develop if you are having a major surgery or if you have an advanced or serious medical condition. You can prevent some of these complications by answering all of your health care provider's questions thoroughly and by following all instructions before your procedure.

General anesthesia can cause side effects, including:

  • Nausea or vomiting.
  • A sore throat from the breathing tube.
  • Hoarseness.
  • Wheezing or coughing.
  • Shaking chills.
  • Tiredness.
  • Body aches.
  • Anxiety.
  • Sleepiness or drowsiness.
  • Confusion or agitation.

What happens before the procedure?

Staying hydrated

Follow instructions from your health care provider about hydration, which may include:

  • Up to 2 hours before – you may continue to drink clear liquids, such as water, clear fruit juice, black coffee, and plain tea.

Eating and drinking restrictions

Follow instructions from your health care provider about eating and drinking, which may include:

  • 8 hours before – stop eating heavy meals or foods such as meat, fried foods, or fatty foods.
  • 6 hours before – stop eating light meals or foods, such as toast or cereal.
  • 6 hours before – stop drinking milk or drinks that contain milk.
  • 2 hours before – stop drinking clear liquids.


Ask your health care provider about:

  • Changing or stopping your regular medicines. This is especially important if you are taking diabetes medicines or blood thinners.
  • Taking medicines such as aspirin and ibuprofen. These medicines can thin your blood. Do not take these medicines unless your health care provider tells you to take them.
  • Taking over-the-counter medicines, vitamins, herbs, and supplements. Do not take these during the week before your procedure unless your health care provider approves them.

General instructions

  • Starting 3–6 weeks before the procedure, do not use any products that contain nicotine or tobacco, such as cigarettes and e-cigarettes. If you need help quitting, ask your health care provider.
  • If you brush your teeth on the morning of the procedure, make sure to spit out all of the toothpaste.
  • Tell your health care provider if you become ill or develop a cold, cough, or fever.
  • If instructed by your health care provider, bring your sleep apnea device with you on the day of your surgery (if applicable).
  • Ask your health care provider if you will be going home the same day, the following day, or after a longer hospital stay.
  • Plan to have someone take you home from the hospital or clinic.
  • Plan to have a responsible adult care for you for at least 24 hours after you leave the hospital or clinic. This is important.

What happens during the procedure?

You will be given anesthetics through both of the following:

  • A mask placed over your nose and mouth.
  • An IV in one of your veins.
  • You may receive a medicine to help you relax (sedative).
  • After you are unconscious, a breathing tube may be inserted down your throat to help you breathe. This will be removed before you wake up.
  • An anesthesia specialist will stay with you throughout your procedure. He or she will:
  • Keep you comfortable and safe by continuing to give you medicines and adjusting the amount of medicine that you get.
  • Monitor your blood pressure, pulse, and oxygen levels to make sure that the anesthetics do not cause any problems.

The procedure may vary among health care providers and hospitals.

What happens after the procedure?

  • Your blood pressure, temperature, heart rate, breathing rate, and blood oxygen level will be monitored until the medicines you were given have worn off.
  • You will wake up in a recovery area. You may wake up slowly.
  • If you feel anxious or agitated, you may be given medicine to help you calm down.
  • If you will be going home the same day, your health care provider may check to make sure you can walk, drink, and urinate.
  • Your health care provider will treat any pain or side effects you have before you go home.
  • Do not drive for 24 hours if you were given a sedative.


  • General anesthesia is used to keep you still and prevent pain during a procedure.
  • It is important to tell your health care provider about your medical history and any surgeries you have had, and previous experience with anesthesia.
  • Follow your health care provider's instructions about when to stop eating, drinking, or taking certain medicines before your procedure.
  • Plan to have someone take you home from the hospital or clinic.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.