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An anesthetic is a drug that causes anesthesia, which is the loss of some or all feeling or awareness. Anesthetics are a safe and effective way to manage pain or keep someone calm during surgery or other painful tests or treatments.

Types of anesthetics

Different types of anesthetics may be used depending on the situation and the test or treatment being done.

Local anesthetic causes numbness or a temporary loss of feeling in one small area of the body. You stay awake during the procedure but have no feeling in the part of the body treated with the anesthetic. A local anesthetic can be given as a needle, spray or ointment. Local anesthetics may be used to numb the skin before a needle or surgical cut (incision).

Regional anesthetic blocks pain in an area of the body, such as an arm or leg. The anesthetic is injected near a cluster of nerves to numb a larger area of the body. An example of a regional anesthetic is an epidural.

General anesthetic causes a loss of consciousness. It may be described as being asleep. But unlike regular sleep, you will not wake up during the procedure. You do not feel the procedure or pain. You are not aware of the procedure, and you do not remember the procedure after you wake up. A general anesthetic is given by intravenous (IV) or by breathing it in (inhalation).

How anesthetics are given

The type and amount of anesthetic used will depend on your age, weight, type of test or surgery, area of the test or surgery, any allergies you have and your overall health.

Before general anesthesia you may need to prepare by not taking certain medicines, and you will probably be told to not drink or eat anything for a certain time before the surgery or test. Your doctor will tell you how to prepare.

General anesthetics are given by an anesthesiologist. This is a doctor who specializes in giving anesthetics. The anesthesiologist will also monitor your heart rate, breathing, blood pressure and temperature while you are under general anesthesia.

A general anesthetic is given by inhalation of gas or by medication through an intravenous (IV).

During an inhalation anesthetic, you breathe in the anesthetic. The anesthesiologist holds a clear plastic mask over your nose and mouth. The mask is attached to a machine that delivers oxygen and the anesthetic drug as a gas. During an intravenous anesthetic, a small IV needle is inserted in the hand and anesthetic medication is given through it.

Side effects

After general anesthesia, the healthcare team monitors you closely for possible side effects. These will go away as the anesthetic wears off. Some common side effects include:

  • fatigue
  • dizziness
  • irritability
  • sore throat
  • dry mouth
  • cough
  • nausea
  • vomiting
  • chills or shaking

Serious side effects such as allergic reaction, brain injury or cardiac arrest are rare, but they are possible. The anaesthesiologist is trained to deal with these problems if they happen and will watch you very closely for them.

Special considerations for children

Preparing a child for anesthesia can help lower their anxiety, make them more cooperative and help them develop coping skills. Parents and caregivers can help prepare children by explaining to them what will happen, including what they will see, smell, feel, hear or taste during anesthesia.

A child’s age and development can affect their fears about anesthesia. Most kids are concerned about getting a needle. A local anesthetic can be applied as a cream to numb the skin before a needle or surgical cut. Depending on the type of procedure, children may be given medicine to help them relax and feel sleepy before going into the operating room where the anesthetic is given. Children are also often given an inhaled anesthetic before any IV is placed.

Younger kids may be afraid of being separated from their parents, so it may help if you can be with them in the room until they fall asleep under general anesthesia. Talk to your child’s anesthesiologist to see if this is possible.

Older children may be afraid of pain, cutting or scarring of the body or waking up during surgery.

To help prepare children for general anesthesia:

  • Let your child know where you will be during the surgery or test. For example, you will be nearby in the waiting room or in the recovery room when they wake up.
  • Explain to them in a way they can understand that the doctor will give them medicine to make them nap or sleep so that they won’t feel anything during the test.
  • Reassure your child that they will not wake up during the surgery or test. They will wake up after.
  • Explain that they may feel a little weird after surgery and that is normal. They may have some pain after the surgery but the doctor will give them medicine to help.
  • Try to create a calm, supportive and soothing environment for your child before and after the surgery or test.

Preparing a child for general anesthesia depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.