Dear Doc.., Recently , while travelling in bus I fell asleep and I slightly struck my head to one of the iron support handle. I didn't experience any pain at the impact zone,but I felt a slight headache later that evening, but it was cured the next morning. I have not developed any symptoms of nausea , dizziness , severe headache, loss of body actions,etc... I only noticed a bump on my skull today when my mom heat treated the impact zone to ease any blood clotting if present... The bump seems to be very hard almost as if like my skull structure... Is it normal to have such shapes/ridge on top of Skull or has it formed because of the impact...??!