When you visit a physician, checking your blood pressure is as routine as taking your temperature or checking your weight. But your blood pressure provides a glimpse into your cardiovascular system and can signal potential risks to your overall health. Know the meaning behind the two numbers that make up your blood pressure.
Blood pressure is a two-number measurement of your heart's function. The top number is the systolic pressure, or the pressure of the blood within the vessels as your heart contracts. The bottom, or diastolic, number is the pressure of blood between the heartbeats, or when your heart rests and refills. The National Heart, Lung and Blood Institute sets the target range at less than 120/80.
When the systolic pressure reaches 140 or higher, or when the diastolic pressure reaches 90 or higher, hypertension, or high blood pressure, is diagnosed.
Systolic and diastolic blood pressure are equally important, but systolic pressure becomes more important after age 50, as studies have found that the risk of cardiovascular disease increases when the systolic pressure is elevated in older adults. The large arteries become more stiff as we age, so the systolic pressure reveals the vessels' flexibility. Meanwhile, diastolic pressure levels off during the 50s and may even begin to fall.
Left untreated, hypertension can, over time, damage blood vessels and organs. But even spikes in blood pressure can be dangerous. When blood pressure reaches 180/110 or greater, hypertentive crisis results. Common symptoms include shortness of breath, severe anxiety and headache. Circulation becomes inadequate, leading to organ damage and even organ failure, as blood vessels are inflamed and may leak. More serious consequences include heart attack, stroke, unconsciousness, eye and kidney damage, fluid in the lungs and memory loss.
When the diastolic pressure is less than 90 and the systolic pressure rises above 140, a condition known as isolated systolic hypertension results. The cause can be a leaky heart valve or hyperthyroidism, or an overactive thyroid gland. Isolated systolic hypertension can lead to serious conditions, like heart disease, stroke, kidney disease and dementia.
Treating isolated systolic hypertension with medicine may also lower the diastolic pressure, so treatment options are carefully considered.
In people 50 and older, isolated systolic hypertension has become the most common form of high blood pressure. Between 15 and 20 million Americans have this form of hypertension.
Patients with high blood pressure may be prescribed beta blockers, ACE inhibitor or diuretics to help lower their blood pressure. These medications lower diastolic and systolic blood pressure, which can lead to low diastolic pressure, which is called hypotension.