Standing up can cause a sudden loss of blood pressure in your brain. This is especially true if you have been sitting in such a way as to partially cut off the blood supply to your legs. The blood rushing back to the deprived area causes the drop in blood pressure.
If this happens often, you may be suffering from hypotension (low blood pressure) and might want to consult your doctor. Hypotension can lead to fainting episodes, among other problems.
Dizziness is a symptom of many different body system conditions and mechanisms. One cause is disruption of the normal feedback to the brain about the body's position in space.
If the gel-like fluid in the semicircular canals (part of the inner ear) are moved too far or in opposing directions by spinning or other rapid changes in position, the "hairs" (cilia) inside the canals send signals to the brain that can confuse spacial orientation. The abnormal motion of the cilia, and other structures in the canals, send conflicting signals to the brain. This unconscious data, sometimes coupled with the information about spacial orientation that the brain is receiving simultaneously from the eyes, can lead to varying degrees of dizziness.
Dizziness can also be caused by changes in the central nervous system and altered states of mind by opioids or other drugs, alcohol, or chemicals. Similarly, vertigo (dizziness) can be caused by anxiety, pain, fear, migraines, dementia and mental confusion, strokes and damaging high blood pressure, concussions and more severe head injuries. Neuropathy (disorders of the nerves), such as that in complications of Diabetes can also create this effect.
Weakness from dehydration, electrolyte imbalance, low blood sugar, low blood pressure, common colds and flu can also cause dizziness.
Anything that creates low oxygenation of the brain (hypoxia) will also cause this symptom. That can range from blood loss and anemia to cardiac and pulmonary diseases. Some examples are: hardening of the arteries in the brain or vessels leading to the brain; clots or occlusions of those vessels; heart rates too fast or too slow; hyperventilation; heart failure or damage from heart attacks; the heart's electrical stimulation malfunctioning (e.g., heart block); pneumonia and bronchitis; Asthma; Allergies; excessive G-Force as experienced by pilots and astronauts; etc.
The fluid in your brain starts spinning. You get dizzy when you get up too fast because when you are sitting down, all the the blood is in you arms and legs, but when you stand up really quick, all of the blood rushes to your head, therefore you either get a headache or get dizzy. Its basically the reaction to the speed of your blood movement.
When you stand up usually your body adjusts your blood pressure so you don't get dizzy. Sometimes the adjustment doesn't happen fast enough. This is called orthostatic hypotension if it happens.
Occasional dizziness or lightheadedness may be relatively minor and the result of mild dehydration, low blood sugar, or too much time in the sun or a hot tub, for example.
Dizziness or lightheadedness may also happen when you stand after sitting for a long time, such as in a lecture, concert or church.
If these symptoms happen only occasionally, it's not cause for concern.
It's called orthostatic hypotension - your blood has collected in your lower areas and it takes a moment for your heart to pump extra blood to your head. Your blood pressure drops for a moment.
When you stand up usually your body adjusts your blood pressure so you don't get dizzy. Sometimes the adjustment doesn't happen fast enough. This is called orthostatic hypotension if it happens.
Occasional dizziness or lightheadedness may be relatively minor and the result of mild dehydration, low blood sugar, or too much time in the sun or a hot tub, for example.
Dizziness or lightheadedness may also happen when you stand after sitting for a long time, such as in a lecture, concert or church.
If these symptoms happen only occasionally, it's not cause for concern.
The lack of blood flowing to your brain.
This can be caused by high blood pressure.
The most common reason that some people get dizzy after a massage has to do with the transition from being relaxed and lying down and then change to a vertical position standing up too fast. If you ever laid out in the sun and then stood up too quickly that you experienced a slight dizzy feeling, then you have experienced the same thing. A good massage will relax you, and then if the massage therapist does not get you up slowly, you may experience dizziness of even fainting.
feeling faint and lightheaded are common in pregnancy; and are usually from low bloodsugar. try to refrain from standing up too fast, turning around too fast or exercising before eating.
If you have been lying down for a while or slouching, blood will start to stay around your brain. When you stand up all the blood flows back into the circulatory system which causes the dizzy feeling you get.
You can get dizzy from not eating , getting up to fast, or even a lot of other reasons. I would ask a Doctor or at least go see a Doctor.
Here's the the full question( had to make it smaller) rarely ill get this flash or even when you stand up to fast and get dizzy/light headed and about to pass out feeling in my head then what ever I was looking at i remember the image perfectly for ever.. I remember my 2 birthday..
This could be meningacocal or cancer
You were dizzy from standing up to fast. Don't do that.
Getting up too quickly. Not drinking enough water. And cut the salt.
You are drunk and your eyes are closed. Actually it would be better to ask your doctor than a website.
Try to rest and drink water :)