Suggest Treatment For Frequent Fainting Spells

I am concerned about the type of fainting spells I ve had on a few occasions lately. Just so you know, I do faint easily... when I am frightened, injured or see trauma. My blood pressure runs on the low side 100/69. However, I have recently had a strange type of fainting spell. They occur at night after I ve gone to bed. I am awakened by a painful calf cramp, then I become dizzy and nauseated and pass out. My boyfreind says once a passout that I start making very strange snorting, grunting noises. When I come too I have a very frightening, disorienting feeling... my entire body feels like it is buzzing and I feel as if I am falling, something feels very wrong & frightening. This is not what I normally experience when I faint. Then I am become very sick feeling with nausea and diarrhea.