Hi David, it's not a silly question at all. It can feel different to different people but to me it's a sudden trembly feeling all over the body, sort of like a fluttering. If I am really low the inside of my mouth goes tingly and then numb. That can be accompanied with a feeling of extreme hunger. Hope this helps. If it happens we have to take something very sugary/sweet in order to bring the glucose levels up fast, some people use pure juice but I tend to use tailor made glucose tabs. x