Quote:
Originally Posted by Willem
By definition, blood pressure is the pressure at the exit of the heart (aorta). It is close to the pressure that you measure in your arm or wrist, provided that you keep it at heart level when measuring BP. The blood pressure is different at different locations in the body, e.g. higher in the feet and lower in the head when standing up.
In inversions, there can be a surge of blood to the head and a corresponding increase in local blood pressure. This short increase in blood pressure in the head (not at the heart) is the one causing potential risks of stroke. Once you are in headstand, the body will attempt to lower blood pressure. For uncontrolled hypertensives this adjustment can be impaired, putting them at greater risk than the rest of the population.
I don't know how the blood pressure measurements were done in the medical studies. Some of the earlier studies may have just calculated the hydrostatic pressure from the distance the head was below the heart. It would be interesting to get hold of the more recent studies, like Gilmore (2002) so see what they have done. Perhaps the doctors on this forum will comment.
|
By definition, blood pressure is the force exerted by the blood to the arterial walls. It is measured in the aorta because its related to the peripheral vascular resistance which peak is found in the aorta.
The problem with a head stand is related to the fact it is much more difficult for return blood from your head to the heart due to simple gravity, and yes, it can cause blood stasis which increases the blood pressure inside your head.
I agree when your pressure is not regulated a little increase might break the brain's regulatory pressure system and cause intracraneal hypertension.
I don't agree on the idea this is the cause of a stroke though. For a stroke you pressure would have to rise at least to numbers close to 200/100. Chronic hypertension though, causes arterial degeneration, including obviously, intracraneal arteries (Willy's Polygon is how the main blood system is called), which can lead on pathologies including "head strokes" (sorry, it's the only word I could think of not being a medical term to help everybody understand).
High Blood Pressure is called the "silent assassin", because you never have a symptom until it is already too late.