Whenever I stand up after sitting for a few hours, I feel extremely dizzy and sometimes my vision just kinda black out and become blur for at least a few seconds. I know this is common if you have been sitting for too long. But I have it very frequently, at least 2-3 times a day. I don't used to have this last time even if I sat down for quite a long period.
I have been eating well and sleeping well. My blood pressure measures 92/62 which I suppose is in the healthy zone. My family and boyfriend said I have lost weight, but I still look the same!
Is there anything wrong with me?
When I have a drop in blood pressure to the point where I get dizzy, I increase my water and salt intake. That seems to help. If you get to the point you experience dyspnea with normal activities or chest discomfort, you definitely need to be seen by a doctor.
My concern here is the possibility of an eating disorder. You stated you
have been told you are losing weight, but you don't see it. Are you trying to
lose weight? Remember there is a right way and a wrong way.
Thank you for your reply!
Nope...in fact I'm eating more than usual, proper 3 meals a day with occasional supper. It's impossible for me to lose weight.. 
I am trying not to sit for long hours and see whether it would help 
Hi carol. Same thing happens to me also very frequently. I was told to increase my water and salt intake. And not to stand up very quickly