High Blood Pressure
High blood pressure is when the force of your blood pushing against the walls of the arteries is consistently too high. High blood pressure is often caused by an unhealthy lifestyle, although it can result from other medical conditions as well.
Blood pressure consists of two components: systolic pressure and diastolic pressure. Systolic pressure is the pressure when the ventricles of the heart contract and pump blood through the body. Diastolic pressure is the pressure between heartbeats, when the heart is filling with blood. High blood pressure (commonly referred to as “hypertension”) is when the force of your blood pushing against the walls of the arteries is consistently too high.
There are generally no signs or symptoms of high blood pressure until it has caused serious health problems (e.g., stroke, heart attack, kidney failure), which is why it is colloquially known as the “silent killer”.
High blood pressure is diagnosed by measuring a person’s blood pressure. There are multiple methods for measuring blood pressure, including using hand-powered cuffs and a stethoscope, semiautomatic monitors (either at the doctor’s office or at home), or ambulatory blood pressure monitors (which collect blood pressure readings several times per hour across a 24-hour period).
Broadly speaking, a systolic and diastolic blood pressure of <120 and <80 mmHg is considered optimal. Hypertension is diagnosed at the doctor’s office if they measure a systolic and/or diastolic blood pressure of ≥ 130 and ≥ 80 mmHg over multiple measurements.
There are five major classes of blood pressure-lowering drugs: angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARBs), beta-blockers, calcium channel blockers (CCB), and thiazide or thiazide-like diuretics. Broadly, these drugs have their effects by reducing blood volume and/or relaxing the smooth muscles that control the diameter of blood vessels.
A combination of an ACEi or ARB with a CCB or diuretic is the preferred initial therapy for most people with high blood pressure. If blood pressure remains uncontrolled, a combination of an ACEi or ARB with a CCB and a diuretic is recommended.
Diet directly affects blood pressure. In most people, sodium reduction reduces blood pressure, and so does increasing potassium intake, whereas alcohol seems to increase blood pressure. A sodium intake of <1,500 mg/day is ideal for people with high blood pressure, but reducing sodium intake by 1,000 mg/day is a good starting point.
The most effective diet for reducing blood pressure is the Dietary Approaches to Stop Hypertension (DASH) diet, which is rich in fruits, vegetables, whole grains, nuts, legumes, and low-fat dairy products and is greatly reduced in added sugar and saturated fat.
Exercise has a powerful effect on blood pressure, and evidence suggests that it’s as effective as some medications. Exercise seems to reduce blood pressure independent of changes in body weight, but the magnitude of blood pressure reduction will increase if weight loss also occurs.
People with high blood pressure should perform at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic exercise per week and two resistance exercise sessions.
In the vast majority of cases (>80%), high blood pressure is caused by lifestyle habits such as unhealthy eating patterns, insufficient physical activity, and excessive intake of alcohol. Consequently, there is a direct relationship between increases in body mass index or waist-to-hip ratio and increases in blood pressure. Genetic variants also influence blood pressure, but they only contribute to about 3.5% of the variability in blood pressure between people.
In about 10-20% of cases, high blood pressure is caused by a separate medical condition (e.g., primary aldosteronism, renal artery stenosis, obstructive sleep apnea). Primary aldosteronism is increasingly recognized as an underdiagnosed cause of high blood pressure and may be responsible in up to 10% of cases.