Could be a wisdom tooth erupting on that side. You need to consult a dentist who will take an X-ray and clinically examine to confirm.
Health Tips
Do hot water gargles with salt and take an anti inflammatory tablet like Combiflam to relieve discomfort. You may need antibiotics which your dentist will prescribe
Answered2018-03-06 03:15:26
Let others know if this answer was helpful