An epidural is an anesthesia medication that is used to block pain by numbing certain parts of the body, according to MedlinePlus. A shot is given in or around the spine, and the area may be numbed with a local anesthetic.
A small tube called a catheter is left in place, which allows more medication to be given as needed, notes MedlinePlus. Normally, an epidural begins to take effect within 10 to 20 minutes. Epidurals are often used during labor and delivery or for surgery in the pelvis and legs. Epidural anesthesia does not have as many side effects or risks as general anesthesia.