There are multiple underlying factors, and lots of remedies/regimens we can do in order to help greatly diminish these issues. I made a video that delves into the subject matter and gives different options/remedies into how we can learn to manage our intense emotions when it comes to ADHD.
If you're interested, the vid is uploaded on my ADHD Youtube Channel. Link to my channel is in my bio description on my profile here (you can click my pic to get there).