This has happened to me 3 times in the space of 2 years:
I'm not sure if its something to worry about, but after the last time I've decided to do some research. I wake up in the middle of the night with an INTENSE headache. The pressure is unbelievable. At first if i sit or stand up the pain fades ( while if i lay down the pain is unbearable), but after a few minutes , sitting or standing doesn't help at all and the pain gets worse. I then feel a sudden wave of nausea and throw up violently. As soon as ive thrown up my headache disappears completely.
This doesnt happen often but it worries me that the pain is SO intense. At times my eyes cant even focus due to the pain.
If any one has any idea WHY this is happening, id really appreciate the information .