<s>[INST] I have a dark lump that is on my tooth/gums in the back top left of my mouth. Its been there a few days, at first it didnt hurt, but after a few days of brushing it hard its starting to hurt. It is red, bleeds when i brush it a lot. What could it be and is it serious? I have a dentist appointment in 2 weeks... [/INST] Hi Dear, Welcome to Chat Doctor. The symptoms you mention in query are clearly showing that there is a formation of dental abscess or endodontic abscess. An abscess is an area of pus that forms as part of the bodies effort to fight a bacterial infection. The bacteria can enter the tooth from upper surface in the form of caries and form abscess at root tip. Sometimes bacteria can enter through gums and cause infection. There can be many treatment options for dental abscess like root canal treatment, Chat Doctor. As you already book appointment with dentist, but It's too late try to consult another dentist for airily appointment. You should take care of certain things till then. Avoid brushing at that particular site, wash that site with warm water, do warm saline rinses several times a day, maintain proper oral hygiene and do Betadine rinses twice a day to prevent infection from spreading. Take ibuprofen or acetaminophen for pain and swelling. Hope your concern has been resolved. Get Well Soon. </s>