While pain and swelling are common signs, you may not have any symptoms. That means the pus pocket has found somewhere to drain.
If you don’t have symptoms, your dentist could spot an abscess through X-rays at a routine exam. He may tap on your tooth to see if it hurts.
If he can’t diagnose the abscess on his own, he’ll probably send you to an endodontist, who’s specially trained to work on abscessed teeth. This dentist can tell for sure if you have an abscess and treat it if you do.