could be low iron, but if it dont happen a lot I wouldnt worry about it.

Yeah. That you've been sitting for too long and/or got up too quickly. The blood rushes to your legs (away from your head) and causes light-headedness while the circulation regulates. If the dizziness persists for more than a few minutes (or randomly occurs without obvious cause), consult your doctor. :)

This has been happening to me a lot lately and a coworker told me to get my blood pressure checked.

Generally it will be low blood pressure, but that is usually just a symptom of something else. Check with a doctor.

It depends. This is related to something called Postural Hypotension or Orthostatic Hypotension IF you exercise often and are in good shape you might occasionally experience dizziness and lightheadedness when you stand up quickly. This is generally nothing serious, and occurs due to a slow heart rate. Cardiovascular exercise makes your heart stronger and a stronger heart has a larger stroke volume. That is, the amount of blood pumped out during each beat is greater, so the heart doesn't have to beat as often. A slow pulse rate is generally an indication of a strong, healthy heart. However, a slow heart rate can sometimes lead to dizziness when you change position. When you stand up quickly gravity pulls blood from your brain towards your feet and blood doesn't return to the brain until the next heart beat. With a slow pulse, this takes a second or two. That is enough time to feel the lack of oxygen, thus the symptom of lightheadedness or dizziness. This results from a decrease in blood flow to the brain, due to a drop in blood pressure upon standing up. As long as it OCCURS ONLY OCCASIONALLY, you don't really need to worry. IF you have CONSTANT and SEVERE dizziness with changing position you should SEE A DOCTOR to rule out an underlying condition such as an irregular heartbeat.

with me normally if its i havnt eaten for a while

It sounds like low blood pressure. If it happens often, or it scares you, you might want to visit your doctor.

low blood pressure probably. Also if you are dehydrated or haven't eaten much.

this happens occasionally to me. i actually collapsed a couple of times, went to ER. doc said one problem was my resting heart rate and blood pressure was much lower than when i stood up, and my heart overloaded and the correction was for me to lay back down, hence all the falling over. otherwise i would get dizzy, eyes would go black, and legs would go numb. he also attributed it to dyhydration of the heart (orthostatic syncopea i think) and the cure for that is to drink lots of water. no more problems as long as i drink enough.

in my case, it's probably blood collecting in my fat ass and not making it's way up to my head.

i heard it can happen more as you get older

it could be anything, i would go to the doctors and get it checked out