Hi, I Have An Extremely Hard, Bone-like Bump Behind My

Hi, I have an extremely hard, bone-like bump behind my uvula in the back of my throat. Was wondering what could be a possible cause for this? I do cough a lot and have had a runny nose on and off for several months now. I first noticed this bump a month or two ago and thought it was sinus related but it never went away. So I'm quite nervous