<s>[INST] My son is 11 years old and plays football. He was at practice today and got tackled. We are now at the emergency room. He hit his head on the ground. He now is getting sharp pains intermittently in his head. That is his only symptom. I know he may have a concussion but I m wondering if it could be anything else? [/INST] Hi,His injury is likely to have caused superficial bruising which will be enough to cause the sharp pains. Signs that may be a cause for concern would be persistent nausea and vomiting, unexpected sleepiness, dizziness or loss of consciousness.Regards,Dr K A Pottinger </s>