Why is it that everytime I stand up after sitting on a chair, I will feel like fainting?

Question

It is like.. I sit on my chair for a long period of time using the computer. Then when I stand up, my head feels very light and my vision seems to be 'white-out' or distorted for a while.. about 8-seconds of duration it will fade off

My dad said it could be lack of vitamins and such

Others said it could be low blood pressure.

Any idea?

Answer 1

Low Blood Pressure? You should see a doctor because that shouldn't happen!

Answer 2

Orthostatic Hypotension

Answer 3

It may be your eyes readjusting if your at the computer alot, happens to me too

If it happens without being on the computer it might be a lack of nutrients or low blood pressure

Answer 4

that happens to me if i stand up too fast. staring at the computer for a long time might not help too much either.  

Answer 5

I'm pretty sure it's normal. Just make sure you drink plenty of water and if it keeps happening often, then go see a doctor.

Answer 6

Low blood pressure did it to me. A couple of times I stood up and wound up on my knees wondering who and where I was. I don't know if I was ever really treated for it, but I learned not to hop up off the couch or out of a chair in a big hurry.