Hi.. Can understand your concern.. As per your complain the most common cause for the swelling can be a deeply infected tooth which leads to infection progressing below the root tips of tooth causing pus formation pain and swelling.. When due to long standing infection the nerves and blood vessels of the tooth becomes dead the tooth is said to be non vital and the tooth has no pain but infection near root tips causes pus formation tenderness and swelling.. I would suggest you to consult a dental surgeon and get evaluated for the exact cause of swelling and get treated.. Till the time you can take painkiller like Ibuprofen as it will help reducing pain and inflammation.. In case of severe pain tablet Ketorol DT can be taken dissolved in half a glass of water.. But this is just a temporary treatment.. Consult a dentist soon to avoid further complications.. Wising you a sooner recovery.. Thanks and regards.. Dr.Honey Nandwani Arora..