Almost pass out when standing from sitting, what can this be ?

[blizzarduk]

I have found lately, for a few months, that when I stand after sitting I feel like I have to pause, and close my eyes and grit my teeth as I get a very light headed feeling, it takes me about 20 seconds or so before I feel I can move. It doesn't seem to matter how long I am sat down either, I can be sat for just minutes and it will happen when standing. Also an odd thing I find is that the feeling differs depending on the chair. If I am sitting on a chair that I sink in to more, like a soft sofa or armchair, then I will feel a lot worse when standing. Chairs, like computer or desk chairs, are less of a problem but still happen.

I also feel my heart beating when I stand. As yet I have not passed out, but it is very annoying as I just have to stand there with eyes winced until the feeling passes.

Also, I am unsure if this is related but I find that if I am lying down on my bed and someone knocks at the door, I have to wait a minute or two before I walk to open the door as I feel a strange sensation that someone is crushing me from upon, or pushing down on me, and my walk goes all funny. If I sit up on the edge of the bed, tell the person to wait, and then stand up a minute later it is okay and I won't get the crushing feeling. I will get a similar feeling when I get out of elevators.

The two above issues might not be related, as I have had the second paragraph problem for longer than the first one. Thanks for any help you can give. I have not yet seen a doctor about it but plan to. I am 38 and male, when I check my blood pressure it seems okay, but not taken it when I feel spacey as the blood pressure machine will take too long to check.

[selmaS]

  Hi and welcome to MedHelp.

Do have your Dr check for low levels of vitamins and minerals as they can cause issues like these. also, a tilt table test could ebb done if levels are fine to check for POTS......Postural Orthostatic Tachycardia Syndrome.....this is a form of dystonia that  affects the flow of blood thru the body that can cause dizziness.