Hello Doc.... ummmm, I wiped out 4 days ago on the ice, flipped right back and smacked the back of my head... felt like I crushed it..... also ....right after.... it felt like there was a massive rush of blood streaming down my skull into my neck...weird.... it was internal.... i didn't break the skin.... I had all the symptoms of a mild concussion.... only lasted a hour, and i haven't had to take any sort of pain relief... thus far .... but my head feels strange... ( p.s. only a walnut size bump at the very top... it is finally gone...) ---- I feel a little dizzy now and then - doesn't last long .... and my head feels weird ....do i need to worry? -- thank you for your time / response - Laurie