For The Past Few Weeks While I Am Sitting Down,

For the past few weeks while I am sitting down, every now and then I feel like I am going to pass out but don't. It usually starts in my right arm, it feels like it falls asleep and then it shoots to my head. I have low blood pressure I am wondering if this has anything to do with it. It almost feels like my brain falls asleep but I am still awake. Strange.