This was not a smooth process. The rise of executive power sometimes hurt important interests and always rubbed against the republican sensibilities that Americans inherited from the founders. From time to time, Congress reaped political benefits from thwarting the president. But today Congress reacts rather than leads.
Some of the causes of low blood pressure include: 1  Getting up after you sit or lie down. 2  This can cause a quick drop in blood pressure called orthostatic hypotension. 3  Standing for a long time. 4  Not drinking enough fluids (dehydration).
A pulse pressure is considered abnormally low if it is less than 25% of the systolic value. The most common cause of a low (narrow) pulse pressure is a drop in left ventricular stroke volume.In trauma a low or narrow pulse pressure suggests significant blood loss (insufficient preload leading to reduced cardiac output).If the pulse pressure is extremely low, i.e. 25 mmHg or less, the cause may be low stroke volume, as in Congestive Heart Failure and/or shock.A narrow pulse pressure is also caused by aortic valve stenosis and cardiac tamponade. pulse pressure is considered abnormally low if it is less than 25% of the systolic value. The most common cause of a low (narrow) pulse pressure is a drop in left ventricular stroke volume.