I am a 59 year old teacher. Night before last, I fell backwards and hit my head on the bottom of a dresser. Went to the emergency room . I had a cut that was approximately an inch long on the side of my head. They said I didn t have a concussion because I didn t lose consciousness and had no problems communicating, etc. I tried to go back to work today after feeling fine and rested. By the time I got there, I started feeling very tired and felt like I needed to go back and rest. Today, as long as I stay on the couch, I am fine, but if I am up for about 30 minutes I get very tired again. Is this normal?