Hi. I ve gone through your query and I can understand your anxiety. Headache post trauma is a common symptom, if there is damage to brain ( head injury). If headinjury is confirmed, then post concussion headaches appear & lasts for few days to months, even for years in few cases. It can be in any forms of headache like tension, rebound, migraine etc. From your history, I can get that your husband met with car accident & there is no documentation about any head injury. In order to rule out the cause, better to do one CT BRAIN . Time being he can take Triptans + Naproxen for pain. Hope I have answered your query. Let me know if I can assist you further. Take care. Regards, Dr. Yogapriya V, General and family physician.