How do you know if have had an allergic reaction to the numbing agent that were given before a filling at office?

Signs and symptoms of an allergic reaction to a local anesthetic may include:

Hives

Difficulty breathing

Swelling of the face, lips, tongue, or throat

Nausea

Vomiting

Lightheadedness

Confusion

Loss of consciousness

If you experience any of these symptoms after receiving a local anesthetic, it's important to seek immediate medical attention.