Hello! Welcome and thank you for asking on HCM! I understand your concern and would explain that your symptoms are related to a head concussion. Regarding the knot on your head, it is caused by the inflammation and edema of the soft tissues sorrounding the scalp related to the trauma. There is nothing to worry about! I recommend you to have some rest for some days, avoid straining physical activity and take painkillers (ibuprofen or acetaminophen) for the pain. You can try to put some ice on the knot. If your situation worsens during the next days ( progressive headache or confusion, nausea, etc), I recommend going to the ER for a physical exam and a brain CT scan to exclude possible delayed intracranial hemorrhage. Hope to have been helpful! Best wishes! Dr. Aida Quka