Thanks for asking the query,
Pain and selling indicates infection in the gums leading to formation of abscess
This infection can be due to plague
calculus deposition, poor oral hygiene
, associated infected tooth, or can be due to nutritional deficiencies or hormonal
changes added with infection.
Go for symptomatic treatment of complete mouth scaling and polishing, root planing and curettage.
If any decayed tooth then get it restored.
Take complete course of antibiotics and analgesics.
Maintain a good oral hygiene, take lukewarm saline gargles and antiseptic mouthwash rinses.
Hope this helps out.