I am facing problem of severe headache from last 1.5 year. I face this issue once in 2 3 months during sleep mostly during early morning hours ( 4 - 5 a.m). Pain is unbearable and I wake up due to this, it continued for around 3 - 4 hrs after taking crocine. I dnt face any other issue except lyk vomiting, nausea, dizziness. Only acute headache which is not bearable to me. Some one please suggest what could be the possible reason for this.