Local anesthetics have made it possible to perform many surgical procedures quickly, with less preparation and a shorter recovery time. General anesthesia and anesthesia that sedates you can cause side effects such as nausea, and an anesthesiologist must monitor you if you are administered these types of anesthesia — during the procedure and for a time afterward. However, with local anesthesia, side effects and complications are rare and usually minor. For example, you may experience some soreness where the medication was injected. In rare cases, you could have an allergic reaction to the anesthetic.