Local anesthetic toxicity is also known as local anesthetic systemic toxicity. This condition can occur when the levels of a local anesthesia in your blood are too high. Local anesthesia is often used during medical and dental procedures to help numb the area of the body that is being operated on. Local anesthesia is usually very safe. However, if you are given too much local anesthesia or it gets injected into your body too quickly into the veins, it can cause symptoms that are harmful. As a result, a person can develop local anesthetic toxicity. Local anesthetic toxicity can cause lightheadedness, confusion, dizziness, abnormal taste, loss of consciousness, or seizures. In cases that are severe, it can even cause death. It is estimated that about one in every 1,000 people who are operated on using local anesthesia may have some degree of local anesthetic toxicity.