Why isolated systolic hypertension?
Certain medical conditions can cause or contribute to isolated systolic hypertension. These include anemia, an overactive thyroid or adrenal gland, a malfunctioning aortic valve, kidney disease, and even obstructive sleep apnea. But usually it results from age-related stiffening of the large arteries. Blood pressure reflects both the amount of blood the heart pumps out every minute (cardiac output) and the pressure the walls of the arteries exert on the flowing blood (arterial resistance). A healthy artery can expand as blood surges through it and return to its original shape when the blood flow ebbs. As we age, our arteries tend to lose their elasticity and therefore their capacity to accommodate surges of blood. Age-related changes, some at the cellular level, also promote the accumulation of fatty deposits (plaque) on the inside of the arterial walls. These changes contribute to the artery-clogging process known as atherosclerosis (hardening of the arteries). Plaque accumulation red
