High blood pressure (hypertension) is known as the “invisible killer.” The patients usually do not have obvious symptoms, so they tend to ignore it and may not even be aware that they have hypertension. However, long-term uncontrolled blood pressure may lead to serious complications such as heart disease, stroke, and kidney failure. So what readings are considered high blood pressure? How do you measure it correctly? What are the warning signs and symptoms? How should patients treat and lower their blood pressure? This article will guide you through these questions with illustrations.

What Is Blood Pressure?

Blood pressure refers to the pressure exerted by the blood on the walls of the arteries when the heart pumps out or receives blood.

The unit for blood pressure is millimeters of mercury (mmHg). Measurement of blood pressure usually records two data at a time: that is, systolic and diastolic pressure, expressed as systolic blood pressure/diastolic blood pressure (mmHg).

The Correct Way to Measure Blood Pressure

If someone has hypertension but fails to notice it due to an incorrect measurement method, it could be problematic. So how do we measure blood pressure correctly?

Time and Location for Measuring Blood Pressure

The best time to measure blood pressure is right after waking up or before dinner, as people tend to be calmer during these times. Find a quiet indoor environment with adequate temperature for blood pressure measurement. Measurements should be taken at the same time every day once the time for measuring blood pressure is determined.

Before Blood Pressure Measurement

Avoid smoking, drinking caffeinated beverages, or exercising within 30 minutes prior to blood pressure measurement. Also, empty your bladder beforehand and do not hold urine.

Five minutes before blood pressure measurement, sit comfortably in a chair and rest quietly.

During Blood Pressure Measurement

Sit in a chair that supports your back, keep your back straight and lean against the backrest, place your feet flat on the ground, relax your whole body, remain quiet, and try not to talk.

Choose a blood pressure cuff that fits the arm circumference, and place it on the upper arm. Remember to wear loose-fitting and lightweight clothing, and roll up the sleeve for measurement. Rest the forearm flat on a table so that the cuff is at the same level as the heart.

Record Blood Pressure

Take two to three blood pressure readings, with a one-minute interval between each reading, and calculate the average value.

Blood pressure readings may vary slightly between the two arms. When taking blood pressure measurements for the first time, it is recommended to measure both arms. Once the arm with consistently higher blood pressure readings has been identified, primarily use that arm for subsequent measurements.

What Reading Indicates High Blood Pressure?

Blood pressure readings are categorized into four stages: normal, elevated, hypertension stage 1, and hypertension stage 2.

For individuals aged 18 and above, two or more consecutive blood pressure measurements with readings consistently above 130/80 mmHg indicate high blood pressure (hypertension). The blood pressure values for each stage are listed in the following table:

It is worth noting that the standards of hypertension may vary across different countries.

7 Possible Symptoms of Hypertension, Watch Out for These Complications

Some patients may have elevated high blood pressure without experiencing any symptoms, which is why it is often overlooked. In fact, by the time symptoms do appear, the patient’s blood pressure may already be dangerously high.

The higher the blood pressure, the greater the risk of damage to blood vessels in major organs such as the heart, brain, and kidneys. Hypertension can lead to serious complications, including atherosclerosis, heart disease, heart failure, stroke, kidney failure, and retinopathy. Notably, high blood pressure is the leading preventable risk factor for heart disease and stroke.

2 Types of Hypertension With Different Causes

So what are the causes of hypertension? Before that, we must first understand the two main types of hypertension:

Primary Hypertension

Over 90 percent of high blood pressure cases belong to the primary hypertension category. The exact cause of primary hypertension is not clear, but it may be the result of multiple factors such as genetics, age, diet, obesity, alcohol consumption, stress, lack of exercise, etc.

Secondary Hypertension

Patients in this category often have hypertension as a result of other conditions or diseases, such as endocrine disorders, kidney disease, congenital heart disease, thyroid or parathyroid disorders, medication use that can cause hypertension, etc.

Once the underlying conditions or diseases are treated, secondary hypertension will often go away, making it a “curable” type of hypertension. The possibility of secondary hypertension needs to be considered in the following cases:

• Hypertension diagnosis at an age younger than 30 or sudden diagnosis after age 50
• Blood pressure reading exceeds 180/110 mmHg
• Blood pressure remains uncontrolled despite taking four or more antihypertensive medications as prescribed
• Sudden worsening of blood pressure despite adequate control with medication

Treating Hypertension With Lifestyle Changes and Antihypertensive Medications

While the exact cause of primary hypertension is often unknown, unhealthy lifestyle and dietary habits can accelerate its progression. Therefore, adjusting lifestyle is the first step in lowering blood pressure for those who have been diagnosed with hypertension.

Lifestyle improvement can be implemented in six steps using the simple formula S+ABCDE:

1. Salt: Reduce salt intake to less than 6 grams per day.
2. Alcohol: Reduce alcohol consumption.
3. Body weight: Lose weight.
4. Cigarettes: Quit smoking.
5. Diet: Adopt good dietary habits, including consuming more fruits and vegetables, less saturated fat, and limiting coffee and soda intake.
6. Exercise: Engage in more physical activity. However, vigorous exercise such as heavy weight training is not recommended.

Thiazide diuretics: These promote the excretion of water and sodium ions in the blood vessels through urine, thus reducing the pressure on the vessel walls.

Calcium channel blockers: Muscle cells require calcium ions to contract properly. Calcium channel blockers, as the name suggests, block the entry of calcium ions into the muscle cells of the heart and blood vessels, slowing down the force of the heartbeat and relaxing the blood vessels, thereby achieving the effect of lowering blood pressure.

ACEI and ARBs: Both of these act on the “renin-angiotensin-aldosterone” system in the human body, which produces hormones that cause blood vessels to constrict, leading to elevated blood pressure. The goal of ACEI is to prevent the synthesis of hormones that cause blood vessel constriction in the system, while ARBs prevent the produced hormones from binding to the muscle cells of blood vessels. Therefore, both ACEI and ARBs can achieve the goal of relaxing blood vessels and lowering blood pressure.