I am Sonia, 40 yrs old. Yesterday I woke up with a severe headache and in spite of taking 3 painkillers the headache did not subside and by evening, the nerves on both sides of my forehead had swollen alarmingly with the headache only becoming worse. When I went to the physician, my BP was extremely high. On taking the medication for BP, the swelling has subsided, but I am curious to know why the swelling happened in the first place...