According to Medical News Today, the numbing effects of local anesthesia last between 30 minutes to four hours. Doctors often determine how long it lasts depending on the amount and strength of the anesthetic used.
Local anesthesia is used to numb a small part of the body before minor surgical procedures, notes Drugs.com. It is designed to drastically minimize pain or block it out completely, but patients usually feel pressure in the area being treated. Unlike general anesthesia, which is injected into veins and causes complete unconsciousness, local anesthesia only affects the specific part of the body where it is administered. According to TeensHealth, local anesthesia is given to patients as a spray, ointment or shot, and the amount doctors administer depends on the age, height and weight of the patient.
Patients are awake when anesthesia is administered and fully aware of what is occurring. Doctors typically do not start the procedure until the area being treated begins to feel numb, which is normally within a few minutes. Some doctors also provide sedatives to nervous patients to reduce anxiety during treatment. After the procedure, the anesthesia slowly begins to wear off, and patients typically experience some post-surgery discomfort. On rare occasions, side effects, including headache, vomiting and dizziness, might occur, according to Medical News Today.