Ears ringing during workout

Hey everyone,

Sometimes during and after an intense cardio workout (usually HIIT) my ears start ringing... it usually feels like a light pressure on my ear, and it makes it more difficult to hear. It goes away during my cool down so I think it's probably related to heart rate/blood pumping. I have generally low blood pressure so perhaps that's related, not sure.

Anyone have any ideas of what this might be and how to stop it? There's no real pain, I just don't know if I should be worried about it. Thanks!!