vision goes black and dizziness

i'm 16 and when i stand up my vision goes black for around 2 seconds and i get so dizzy that i nearly fall over. This happens even if i have only sat down for a minute and has been happening nearly everyday for maybe just over a month. I'm not dieting and have no eating disorder is there something wrong?

[Singingloonie]

This used to happen to me when I was your age. Have your blood pressure checked - it may be running low. Keep up on your fluids.

[MxGrl]

This always happens to me! I get up from sitting or laying down and I get sort of dizzy and my vision goes black. I hate it! Try getting up slower and make sure your drinking enough water, but I hear about this happening to a ton of people so it's probably no big deal. I also just heard that eating foods that have a lot of iron helps.

[simpleALEX]

I have the exact same problem, but have had it for so long that i cant even remember when it first started happening and i'm now 17. There are many different theories but those that i have found most appropriate concerning this issue are namely; Vasovagal syncope and Orthostatic Hypotension. It is also possible that these issues are linked to Heart disease, poor diet and Low blood pressure which be very could serious issues but none are confirmed to have direct relation to the dizziness and vision blackouts. I would advise you get it checked up ASAP to eliminate any underlying possibilities of more serious issues such as Heart disease etc...
anyway i hope i have helped and i wouldn't worry about it too much just try to stand up slowly and prepare before you stand up :) i mean its become so normally to me that i just continue doing what i was doing as though nothing was happening and often stumble around for the three seconds i blackout like someone looking for something in the dark haha lol