Hi Dear, Welcome to HCM. Understanding your concern. Thanks for your concern . The lump Above the tooth is periapical abscess . This occur when infection travel through the tooth and form beside the gum and reach the root of the tooth . This infection form pus there and sometimes make opening through the gum for drainage ,which is known as sinus. I would suggest you to consult dentist or endodontist (as you mention) for proper evaluation. Doctor will order x-ray to look for extent of infection, bone support and root of the tooth . There are few treatment options :- - If the infection is mild and didn t affect the root of tooth the doctor will prescribe along with painkillers . - If the infection is sever and root of the tooth is also get involved the doctor may perform root canal and left open for few days for drainage of pus. In some cases apicoectomy will be performed. - If there is bone loss and infection is severe the extraction of tooth should be done along with prescription of antibiotics. Do warm saline rinses several times a day and take ibuprofen (if not allergic ) or acetaminophen for pin and swelling. Hope your concern has been resolved. Best Wishes, Dr. Harry Maheshwari