Why would Diastolic pressure decrease if blood volume is being lost?
Diastolic BP is the pressure that exists while the heart is at rest. This is a general indication of hydration if there is no other factor affecting the BP such as shock or medications. As a person loses volume from bleeding, dehydration etc, the pressure during this resting state goes down. Diastolic BP doesn’t decrease as HR goes up but more likely the HR increases in response to a decrease in BP. The body tries to compensate for the decrease in volume by increasing the HR to maintain a more steady state for cardiac output.
