General Anesthesia

General Anesthesia


General anesthesia uses medicines that make you unconscious. It affects your whole body.

When it's used, you will be unaware. You won't feel pain during the procedure. It also causes you to forget things from right before, during, and right after the procedure.

It also affects many of your body's normal functions, such as those that control breathing. So you will be watched closely. Your body's functions will get support to keep you safe.

How it's done

Anesthesia medicine may be given through a needle in a vein (intravenous, or IV.) Or it may be inhaled. Sometimes it's given both ways. During the procedure, an anesthesia specialist will watch you closely. They will adjust the medicines as needed to keep you safe and comfortable.


Major side effects are not common. But all types of anesthesia have some risk. Your risk depends on your overall health. It also depends on how you respond to the medicines that are used.

Serious but rare risks include breathing problems, heart problems, and stroke. Malignant hyperthermia is an extremely rare but very serious reaction that can occur with some anesthesia medicines. It can be deadly. The chance of having this reaction may be passed down in families.

Some health conditions increase the risk of problems. Your anesthesia specialist will ask you about any health problems you have. You will discuss things that can raise your risk. These include sleep apnea; obesity; and heart, lung, or liver disease.

How to prepare

You will get a list of instructions to help you prepare. Your anesthesia specialist will let you know what to expect when you get to the hospital, during the procedure, and after. They will talk with you about the risks and benefits of anesthesia. If you have questions, be sure to ask.

Some things can raise your risk for problems with anesthesia. These include smoking, sleep apnea, and being overweight. Don't smoke for as long as possible (but at least 1 month) before your procedure. If your doctor suggests it, also try to lose weight beforehand. If you have a CPAP machine for sleep apnea, make sure to use it.

Many people are nervous before they have anesthesia. Ask your doctor about ways to relax ahead of time. Relaxation exercises may be one option.

If you will go home on the same day, arrange for someone to take you home.


Current as of: October 20, 2022

Author: Healthwise Staff
Medical Review:
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
John M. Freedman MD - Anesthesiology
Heather Quinn MD - Family Medicine
Donald Sproule MDCM, CCFP - Family Medicine