Anesthesia FAQ

Anesthesia is the use of medications, called anesthetics, that temporarily block pain signals from reaching the brain during a procedure or surgery. They interrupt the transmission of sensory information from the site of the procedure to the brain’s pain centres, effectively numbing the area.

• Local anesthesia numbs a small, targeted area. You stay awake and alert, for example during a skin biopsy.
• Sedation, or “twilight sleep,” brings a relaxed, drowsy state. You are not fully unconscious but are less likely to remember the procedure, as is common for wisdom-tooth removal or some colonoscopies.
• Regional anesthesia blocks pain in a larger part of the body, such as an arm or the lower torso, alone or with sedation. An epidural for childbirth is a familiar example.
• General anesthesia makes you fully unconscious and insensitive to pain, allowing more extensive surgery involving the head, chest or abdomen.

The type used depends on the procedure and its complexity, and is decided with your care team.

Local anesthesia usually begins with a small prick, then tingling or numbness. The area may feel heavy or swollen; you can sense touch or pressure, but pain is blocked. You remain fully awake.

Regional anesthesia, such as an epidural, brings a spreading numbness over a larger area, which may feel heavy or disconnected. Some patients describe a warm, comfortable sensation. You may be awake or lightly sedated.

General anesthesia usually starts with a sedative through your IV that makes you deeply relaxed. As the anesthetic takes effect you drift off, and for most people it feels as if only a second passes before waking in the recovery room. Grogginess, dry mouth or mild nausea are common on waking and pass as the medication wears off.

Most side effects are mild and short-lived. They depend on your health and the procedure:

• Common: hunger or thirst, nausea, vomiting, headache, sore throat, tiredness, dizziness and confusion. These usually settle on their own.
• Bladder: difficulty urinating or recognizing the need to, or brief leakage after a catheter is removed.
• Bruising and soreness where a needle or IV was placed, which typically heals without treatment.
• Mouth or teeth: minor cuts to the lips or tongue from a breathing tube.
• Allergic reactions: rash, hives, swelling, airway inflammation or low blood pressure.
• Awareness: a rare complication where an event is unintentionally recalled, which can lead to distress or sleep problems.
• Lingering effects: subtle memory or problem-solving difficulties from anesthetic medications.

Your care team can give additional medication to manage pain and nausea.