ata shows that hundreds of millions of people around the world have hypertension, while almost 50% of elderly and 20-30% of middle-aged people in Hong Kong are suffering from the disease. Hypertension is often known as the “invisible killer”. Generally speaking, patients do not have obvious symptoms in the early stage and this usually leads to delay or lack of treatment and may eventually lead to severe complications, e.g. heart disease, stroke, renal failure and even death.
(This article is the translated copy from Traditional Chinese version. If there is any conflict or ambiguity between the English and Chinese versions, the Chinese version shall prevail.)


Most people with hypertension do not have obvious symptoms and it is usually detected in a routine body check. A small number of patients may have symptoms of headache, dizziness and fatigue.


Since hypertension cannot be identified easily, adults should  have blood pressure measured at least once every 2 years, for early detection of the disease.

Before understanding hypertension, we need to know what blood pressure is. The beating of the heart can pump blood around the body. When blood is pumped into the arteries, the pressure pushing against the arterial walls is called “blood pressure”. “Systolic pressure” or “upper pressure” is the pressure exerted on the arterial walls when the heart contracts. Diastolic pressure” or “lower pressure” is the pressure exerted on the arterial walls when the heart relaxes. Blood pressure is generally measured in millimeters of mercury (mmHg).


According to the definition by World Health Organization, hypertension is a  reading of blood pressure greater than 140 (higher pressure) over 90 (lower pressure) mmHg with repeated measurements when the person is resting.


The risk factors are:

  • Age: the risk increases with one’s age
  • Family history: people are prone to hypertension if their families had it before
  • Weight: being overweight or obese
  • Diet: too much salt (sodium) in the diet for a prolonged period
  • Lifestyle habits: smoking, drinking, stress and lack of exercise

Prevention of hypertension starts with good living habits:

  • Salt is mainly made of sodium and high sodium in diet will lead to hypertension. Beware of the intake of salt in daily diet, e.g. reducing the consumption of smoked or pickled food with a high salt content. Herbs, spices or lemon juice may be used to replace salt or MSG (a flavour- enhancing compound) in cooking.
  • Eat more vegetables and fruits
  • Quit smoking and reduce alcohol consumption
  • Weight control
  • Regular exercise: lack of exercise will affect the flexibility of blood vessels, which causes stiffening of the vessels and induces hypertension.
  • Keep your mind relaxed

Hypertension can be categorized into two types, primary and secondary, with  different causes:


l   Primary hypertension: around 90% of hypertension cases are primary, with no identifiable causes and mostly related to heredity, personality, mental stress and obesity.

l   Secondary hypertension: hypertension mainly caused by other illnesses or change in health conditions, e.g. renal disease and endocrine disorder (disorder of the endocrine glands that secretes hormones). Blood pressure of the patient will be back to normal if the illnesses are cured.


The easiest and simplest way is to use a blood pressure meter to measure your blood pressure.


If needed, a doctor will arrange further examinations for the patient, such as blood test, electrocardiogram (an electrical recording of the heart to check if it is functioning properly), chest X-ray examination, urine test and fundus (the interior surface of the eyes) examination, etc. to identify the cause of hypertension and the potential harm to internal organs.


Doctors will prescribe appropriate drugs to the patient to lower his blood pressure.  Common drugs used for treating hypertension include diuretics, beta blockers , calcium channel blockers, angiotensin-converting enzyme inhibitors  angiotensin II receptor blockers,  alpha blockers and vasodilators, etc. Patients should take medicines prescribed by their doctor according to the dosing schedule. If they do not feel well after taking the medicines, they should consult their doctor as soon as possible. Medication works well generally.
To maintain good lifestyle habits
People with hypertension should quit smoking, reduce drinking, control body weight, pay attention to diet, avoid excessive salt intake and perform physical activities regularly.  For more advice and information on exercise, please consult professionals or visit the Exercise Prescription website of the Department of Health (hyperlink: http://exerciserx.cheu.gov.hk).


Uncontrolled hypertension can cause the following complications:

—   Arteriosclerosis (blood vessels that supply oxygen and other nutrients to the body's organs harden and become narrower): Arteriosclerosis can cause serious diseases, e.g. heart disease and stroke.

—   Aneurysm (a swollen blood vessel): uncontrolled hypertension can make a blood vessel wall thinner and bulged, and result in aneurysm. It could be fatal if the aneurysm bursts.

—   Heart failure: rise in blood pressure will increase the resistance of blood vessels, placing an added load on the heart; and will result in heart failure.

—   Stroke: the bursting of an aneurysm in the brain can cause stroke.  Uncontrolled hypertension can also cause blood clots in the carotid artery (arteries in the neck), and if the blood clot enters the brain, it can cause embolic stroke.

—   Renal failure: uncontrolled hypertension will affect the arteries in the kidneys, causing damage to kidney function.

—   Retinopathy (damage to blood vessels of the light-sensitive tissue at the back of the eye): uncontrolled hypertension will affect arterioles (branches of arteries) in eyes, causing lesions.


Patients should pay return visits regularly and take medicines according to medical advice. In general, hypertensive patients have to be on medication for a prolonged period and they must not adjust the dosage themselves. When traveling, they should bring along enough medicines for use. They can also measure and record their blood pressure regularly for health monitoring purpose. Good lifestyle habits can help control the disease.

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