Hi Am 21years Old I'm 5'2 And Weigh 120 My

Hi am 21years old I'm 5'2 and weigh 120 My question is under my tongue. Those two side long veins we have well my right side one was feeling sort of like when i have a cold sore. That was yesterday and today it just got all flary red from top to bottom but it is not swollen or any other color? Is it something bad because it only hurts when its touched.