General anesthesia is a combination of medications that a person inhales through a mask or receives through a needle in a vein to cause the person to become unconscious. General anesthesia affects the whole body, including the brain, heart, and lungs, and therefore increases a person's risk for side effects, most of which are minor and can be easily managed.
The risks of general anesthesia vary according to the person's health condition, age, and other factors, as well as the experience level of the doctor giving the anesthesia (anesthesiologist).
The anesthesiologist attempts to maintain a balance of medications while carefully monitoring the person's heart, breathing, blood pressure, and other vital signs. He or she will adjust the anesthesia based on the person's physical responses during the surgery.
Rare but serious risks of general anesthesia include:
- Irregular heartbeat (arrhythmias).
- Dangerous increases or decreases in blood pressure.
- A rapid increase in body temperature.
- Trouble breathing.
- Collapse of blood vessels because of low blood pressure.
- Heart attack or stroke.
- Death because the heart stops (cardiac arrest) or from complications such as changes in heartbeat, blood pressure, body temperature, or breathing.
Serious side effects of anesthesia are uncommon, especially in people who are otherwise generally healthy. If you have any medical problems, such as heart, lung, kidney, or endocrine conditions (including diabetes), tell the person who will be giving the anesthesia (the anesthesiologist or nurse anesthetist). Also tell him or her about any medications you take and about any allergies you have.