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Hypertension, or high blood pressure, is a serious medical condition that increases the risk of heart, brain, kidney, and other diseases. In Hong Kong, 1 in 10 people has hypertension; however, half of those with hypertension are usually unaware of their condition, as hypertension could be asymptomatic. Wonder how hypertension is diagnosed? What are the normal blood pressure ranges? How is hypertension treated? Find out the answers through our guide to hypertension.
Hypertension means high blood pressure. Blood pressure is the pressure exerted on blood vessel walls as the heart pumps. Normal blood pressure is required to push blood through the body so that oxygen and nutrients can reach all tissues. Blood pressure can rise and fall depending on heart function, blood vessel health, and many other reasons. It fluctuates throughout the day and is influenced by emotions and physical activity. For example, blood pressure increases with anger or anxiety and drops during rest or sleep.
Normally, an adult should have a systolic blood pressure below 120 mmHg and a diastolic pressure below 80 mmHg (also written as 120/80mmHg). Hypertension refers to a persistent elevation in systolic blood pressure of 140 mmHg or above or diastolic blood pressure of 90 mmHg or higher (written as >140/90mmHg).
Patients with hypertension can be asymptomatic. As there are usually no symptoms of high blood pressure, regular blood pressure measurement is required to detect blood pressure abnormalities and treat them as soon as possible before any complications arise. Adults are recommended to check for their blood pressure at least once a year, while elderly over 75 should visit the doctor and measure their blood pressure at least twice a year.
Hypertension can be classified into primary (essential) hypertension or secondary hypertension depending on their causes.
Around 95% of hypertension are primary. The exact causes of primary hypertension are usually unknown, but certain risk factors can increase the chance of developing high blood pressure, including:
Secondary hypertension is caused by underlying health conditions or medications. Risk factors of primary hypertension contribute to the severity of secondary hypertension as well. Health conditions that cause secondary hypertension include:
The majority of hypertensive patients show no symptoms. Hypertension is usually discovered during a routine check-up or until complications arise.
Even if hypertension presents signs and symptoms, they are usually not specific and do not appear until the high blood pressure has reached a severe or life-threatening level. People with extremely high blood pressure may experience these symptoms and require immediate medical attention:
If hypertension is not regulated well, serious complications may occur. Common complications of hypertension include:
Blood pressure is generally measured in millimeters of mercury (mmHg). It is classified into systolic blood pressure and diastolic blood pressure:
Blood pressure levels can be categorized as follows:
Categories | Systolic blood pressure | Diastolic blood pressure | |
Normal blood pressure | < 120 mmHg | and | < 80 mmHg |
Prehypertension | 120 - 139 mmHg | and/or | 80 - 89 mmHg |
Hypertension | > 140 mmHg | and/or | > 90 mmHg |
Grade 1 Hypertension | 140 - 159 mmHg | and/or | 90 - 99 mmHg |
Grade 2 Hypertension | 160 - 179 mmHg | and/or | 100 - 109 mmHg |
Grade 3 Hypertension | > 180 mmHg | and/or | > 110 mmHg |
There are multiple guidelines that define hypertension ranges slightly differently. In Hong Kong, physicians generally refer to 140/90 mmHg as the boundary for hypertension. However, some physicians may apply stricter guidelines and diagnose a patient as hypertensive if the blood pressure is over 130/80 mmHg constantly depending on individual conditions.
Most people do not know their blood pressure until regular body checks. Prehypertension is a state before hypertension and indicates a high risk of high blood pressure development. Steps should be taken to improve your health and regulate blood pressure when prehypertension is reached.
Note that an occasional increase in blood pressure above the normal blood pressure range may not indicate hypertension, such a rise can be a normal physiological response due to stress or other conditions. If hypertension is suspected, seek medical advice immediately and consult your physician on available lifestyle changes and treatment options.
Blood pressure is measured using a sphygmomanometer, also known as a blood pressure monitor. There are a few types of different sphygmomanometers, among which the manual and digital meters are most commonly used by physicians and the public respectively. Doctors may ask hypertensive patients to record their blood pressure at regular time periods daily by themselves.
Steps to measure the blood pressure yourself by a digital meter
High blood pressure is mainly diagnosed by blood pressure measurements by physicians. If your physician measures a record of blood pressure that is over 120/80 mmHg continuously (prehypertension) or is 140/80 mmHg or above consistently (hypertension), the physician will diagnose you hypertensive.
When such high blood pressure is recorded, your doctor may also measure your heart rate, calculate your BMI, perform physical examinations and other tests to confirm the diagnosis and check for any underlying causes of hypertension.
Patients with hypertension are advised to make healthy lifestyle modifications. You should keep in mind the following to monitor and lower your blood pressure:
If hypertension remains consistent after carrying out the above lifestyle modifications, the risk of developing complications is higher. Doctors may prescribe the following antihypertensive agents along with advice on lifestyle changes to regulate your high blood pressure:
Although you may not experience any symptoms of high blood pressure, you must take the prescribed medications. This is very important to prevent those fatal complications of hypertension from developing. The management of hypertension highly depends on your commitment to combating high blood pressure. Be proactive in self-management and adopt healthy lifestyle practices, take your antihypertensive drugs on time, record your blood pressure regularly, attend medical check-ups on a regular basis to treat hypertension properly.
Adopting a healthy lifestyle is the most fundamental in preventing hypertension, such habits to prevent hypertension can be summarized as follows:
If you or your loved one is suffering from hypertension, you may get more help from the following organizations:
Normal blood pressure for a healthy adult is 120/80 mmHg or below. Any blood pressure higher than 120/80 puts you at risk of high blood pressure (hypertension) and other cardiovascular problems. Maintain or lower your blood pressure by a healthy lifestyle, a low-sodium diet and regular exercise.
Hypertension rarely shows signs and symptoms at the early stage. You might have high blood pressure if you experience non-specific symptoms like lightheadedness, dizziness, headache or nose-bleed and will require immediate medical treatment. Make sure to regularly check your blood pressure to detect hypertension as early as possible.
Your blood pressure may rise due to unhealthy lifestyles, stress, high-sodium diet, smoking, or alcohol consumption. Certain risk factors like heredity, age, overweight or obesity, and lack of exercise can increase your risk of hypertension and other health problems.
Your blood pressure measurement may always be higher in clinics than it is measured at home. This is known as the “white coat syndrome”. It happens when you become anxious and nervous in a clinical setting. During a blood pressure test, stay relaxed by keeping yourself in a comfortable position, getting enough rest, and maintaining your breathing pattern.
This article was medically reviewed by Dr. Adrian Cheong 張仁宇醫生. Dr. Cheong is a cardiologist practicing at the Virtus Medical Group now. He graduated from the University of Oxford and spent years working in the UK, including at the Royal Brompton and Harefield Hospitals. Dr. Cheong is particularly interested in dealing with coronary artery disease, valve disease, heart failure, minimally invasive surgery on arteries, veins and valves, etc.
This article was independently written by Healthy Matters. It is informative only and not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be relied upon for specific medical advice.
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