“What are the side effects of regional anesthesia?”

The answer depends on the type of regional anesthesia and the procedure involved. In general, most regional anesthesia is well tolerated and wears off in a couple of hours to a couple of days, depending on the technique. Complications and side effects are rare and minimal. If you have any questions about your options, discuss it with your surgeon and anesthesia team.
Good luck!

Nerve injury from the block is a very rare occurrence, but mostly side effects are mild like drop in blood pressure or increased heart rate.

What kind of procedure are you having? Usually problems are related to the medication used and the site of injection, if there is a permanent nerve damage from problem with medicine or injection in the nerve itself. For details, you must talk to your anesthesiologist and the surgeon.