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 medical conditions can cause low blood pressure. These include: 1  Pregnancy. 2  Because a woman's circulatory system expands rapidly during pregnancy, blood pressure is likely to drop. 3  This is normal, and blood pressure usually returns to your pre-pregnancy level after you've given birth.
It could be a neuro cause like in Cushing's Triad, (bradycardia, widening pulse pressure and irregular respirations). Or it could be a cardiac cause such as cardiac tamponade where you get a narrowing pulse pressure do to the impaired filling ability of the heart. narrow pulse pressure is also caused by aortic valve stenosis and cardiac tamponade. A pulse pressure is considered abnormally low if it is less than 25% of the systolic value.