Hello dear, Thanks for being on healthcaremagic.com.If you would have presented to me as an outpatient,I would have made the following clinical explanation- You are likely a case of acute onset primary headache(Most common primary headache disorders are migraine and stress headache).I am saying primary headache because if it would have been an acute onset secondary headache(headache which is due to some intracranial pathology like brain tumor,brain infection),it would have caused some additional symptoms like clouding of consciousness,double vision or loss of vision.Out of primary headache,as I said that it can be migraine or Tension type headache-please observe some features if present: 1)nausea 2)Photophobia and phonophobia(headache worsens on exposure to bright light and sound) 3)Visual aura If these symptoms are present,it goes in favour of migraine otherwise it can be stress headache too. I would like to advise to meet your physician so that he takes the detailed history to meet a diagnosis.Since it is a case of acute onset headache in young,he may also get a brain imaging study done to rule out intracranial pathology.I hope it helps.