The reason you feel dizzy after getting up suddenly is that your blood has to move back up to your head, and it can not always always do this as fast as you can move your head.
So you do not have sufficient blood at that moment, and since blood provides the oxygen your brain needs at all times to function, so it pumps blood to protect itself by keeping essential things fed with blood and others not. The blood stays lower only for a few seconds, but its enough to give you the giddiness or dizziness.
If you remember as a child you had a similar reaction when you spun round and round and then stopped, but the worldkept turning and the trees and you. You could not stop turning, and then fell down, and it was still turning. Your balance system in your inner ear contains a liquid which keeps turning, convincing your brain that you are still turning even when you are not.
People with low blood pressure suffer from dizzy spells more than others.
So you do not have sufficient blood at that moment, and since blood provides the oxygen your brain needs at all times to function, so it pumps blood to protect itself by keeping essential things fed with blood and others not. The blood stays lower only for a few seconds, but its enough to give you the giddiness or dizziness.
If you remember as a child you had a similar reaction when you spun round and round and then stopped, but the worldkept turning and the trees and you. You could not stop turning, and then fell down, and it was still turning. Your balance system in your inner ear contains a liquid which keeps turning, convincing your brain that you are still turning even when you are not.
People with low blood pressure suffer from dizzy spells more than others.
