I have had a weak headache all day, every day, for more than 20 years. Occasionally I will have very bad headaches, visual stuff etc. but there is always a back

I have had a weak headache all day, every day, for more than 20 years. Occasionally I will have very bad headaches, visual stuff etc. but there is always a background, low-level headache. It's weak enough that I frequently forget about it, but if at any given point in the day I ask myself, "do I have a headache", the answer is always "yes". No idea what the origin is other than maybe some concussions when I was ~19 -- I'm not too stressed about it but very curious to hear if anyone here has experienced something similar or has any bright ideas :)