Why do we get dizzy when we stand up too fast?

Answer 1

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.

Answer 2

Standing up quickly causes a drop in blood pressure, which results in a decrease in blood-flow to your brain. This temporary decrease in blood-flow causes you to feel light-headed for a few seconds.

Answer 3

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.

Answer 4

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.

Answer 5

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.

Answer 6

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.

Answer 7

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.

Answer 8

The presure in the air is higher than is was at the level of height you were at before you got up, and depending on how fast you stand up the level of dizzyness may differ.