Anesthesia works by changing how the brain and nervous system send signals, so you do not feel pain, move, or remember the procedure. General anesthesia makes you unconscious and unaware, and it is reversible. During surgery, the anesthesiologist watches your breathing, heart rate, blood pressure, and other vital signs, then reverses the medicine when the procedure is done.

The drugs work in a few main ways. They boost calming signals in the brain, especially through GABA receptors, which are like “brakes” on brain activity. They also reduce exciting signals, such as those using glutamate, acetylcholine, and serotonin. This lowers brain cell firing and disrupts communication in large brain networks that support wakefulness, memory, and movement.

Different anesthetic drugs can work in different ways, but the overall effect is the same: loss of awareness, less pain, and less movement. Some are given through a mask as gas, and some through an IV. After surgery, it may take a day or two for the medicine to fully leave your system, so you may feel sleepy or have slower reflexes for a while.