Introduction

Blood pressure varies with age, sex, level of physical exertion and emotional changes. Hypertension means a persistent raise in blood pressure. According to the World Health Organization, it is defined as systolic/diastolic pressure persistently higher than 140/90mmHg. Hypertensive patients are predisposed to cerebrovascular disease and heart diseases. There is also an increased risk of renal failure, heart failure, peripheral vascular disease and retinopathy in hypertensive patients.

Situation in Hong Kong

Hypertension is an important risk factor for heart diseases and cerebrovascular diseases. The Population Health Survey 2003/2004 revealed that the prevalence of hypertension among people aged 15 and above was 27.2%, with 30.1% for males and 24.9% for females. The prevalence of hypertension increased with age, from 5.2% for people aged 15-24 to 73.3% for people aged 75 and above. The survey also revealed that less than two-thirds (62.9%) of people had their blood pressure checked by health professional in the past five years.

Symptoms

Hypertension seldom causes symptoms until complications develop. However, extremely high blood pressure may cause symptoms like dizziness, visual disturbance, headache, fatigue and facial flushing.

Risk factors

In over 90% of cases, no specific cause can be identified. These cases are diagnosed as having primary hypertension. Some factors such as obesity, high salt intake, stress and family history of hypertension may be related to the disease. In a small minority of patients, specific causes may be identified. These include renal diseases, endocrine diseases and some drugs.

Prevention

Balanced diet, physical activity, and prevention of obesity are useful. Reduce the consumption of food high in salt content. Periodic checks for blood pressure can detect hypertension early.

Related information

For more information on hypertension, please visit the website of our Health Zone and the Hong Kong Reference Framework for Hypertension Care for Adults in Primary Care Settings (for health care professionals).