anesthesia

Meaning of anesthesia: General anesthesia is not deep sleep, since a sleeping person can be roused by noise or touch and an anesthetized one cannot.

Definition of anesthesia

Anesthesia is a controlled, reversible loss of sensation or of consciousness produced with drugs, so that surgery and other procedures can be carried out without pain. The form used is matched to the procedure: numbing a small patch of skin, blocking sensation across a whole region, or suspending awareness entirely while breathing and circulation are supported and monitored throughout.

How anesthesia is built

an esthesia anesthesia
  • a-, an- Prefix · Greek without, not, absent
  • -esthesia Suffix · Greek sensation, feeling

A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.

What are the forms?

FormWhat it affectsAwareness
LocalA small area, numbed at the siteFully awake
RegionalA limb, or everything below a level of the spineAwake or lightly sedated
SedationThe whole body, to varying depthsDrowsy to barely responsive; often no memory afterward
GeneralThe whole body and the brainAbolished

Local anesthesia suits a skin biopsy or dental work. Regional anesthesia, including spinal and epidural techniques and nerve blocks, covers joint replacement and childbirth. General anesthesia is used where stillness, airway control or the extent of surgery demands it.

What does general anesthesia actually involve?

It is not one drug but a combination, each supplying one component: unconsciousness, absence of memory, pain relief, and muscle relaxation where the surgery requires it. Because relaxants can weaken the muscles used for breathing, a tube or airway device usually takes over ventilation, and the depth of anesthesia is adjusted continuously against what the surgery is doing. That is why anesthesia is a live process rather than a single injection at the start.

What is monitored, and what happens afterward?

Standard monitoring follows oxygen level, exhaled carbon dioxide, heart rhythm, blood pressure and temperature, and often the concentration of anesthetic gas. Recovery is staged: waking, then a period in a recovery area where breathing, pain and nausea are watched until reflexes return. Common after-effects are sore throat from the airway device, nausea, shivering and grogginess. Awareness under general anesthesia, in which someone recalls part of the operation, is rare and is one reason depth is tracked rather than assumed. Older adults sometimes experience confusion for a period afterward, which is monitored separately from the anesthetic itself.

Used in a sentence

The procedure was performed under general anesthesia in the operating room.

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Good to know

General anesthesia requires closer monitoring of breathing and circulation than local anesthesia, since it affects the entire body's level of awareness rather than sensation in one limited area.

Word origin

Where “anesthesia” comes from

Formed from Greek an-, meaning without, and aisthesis, meaning sensation, describing a state in which the ability to feel is temporarily removed.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.