High Blood Pressure (Hypertension)
Hypertension is a chronic condition characterized by persistently elevated arterial blood pressure. Usually, high blood pressure does not cause noticeable symptoms, and patients often discover they have it only after developing complications. Hence, it is often called the “silent killer”. According to a population health survey conducted by the Department of Health from 2020 to 2022, about one-third of Hong Kong residents aged 15 to 84 were found to have hypertension during health check-ups. The overall prevalence of hypertension increases with age, from 4.9% in the 15-24 age group to 57.4% in the 65-84 age group.
Blood Pressure Standards
When the heart pumps blood through the body, it exerts force on the vessel walls, creating “blood pressure”. The heart’s contraction (systole) and relaxation (diastole) produce two numbers when measuring blood pressure:
| Blood Pressure Level | Systolic B.P. (mmHg) | Diastolic B.P (mmHg) |
|---|---|---|
| Normal | <120 | <80 |
| Elevated | 120-129 | <80 |
| Hypertension (Stage I) | 130-139 | 80-89 |
| Hypertension (Stage II) | >140 | >90 |
| Hypertension Crisis (Consult doctor immediately) |
>180 | >120 |
Maintaining blood pressure within normal ranges is vital for health. Excessively high blood pressure can cause vessel wall rupture leading to stroke, while too low blood pressure may impair blood flow to organs, causing dizziness, weakness, etc. Blood pressure can fluctuate throughout the day due to physical activity, posture, emotional stress, and sleep quality.
Hypertension Definition
Based on the AHA guidelines, a blood pressure reading of 130/80 mmHg or higher in adults qualifies as hypertension. It can cause serious health issues such as stroke, myocardial infarction, renal failure, vascular blockage, aneurysm rupture, and retinal bleeding. If your blood pressure is in the pre-hypertensive range, it’s important to recognize and modify lifestyle habits to prevent progression to full hypertension.
Causes and High-Risk Groups of Hypertension
Hypertension can be classified into primary (essential) and secondary types. Most patients have primary hypertension, which has no clear or specific cause but is associated with genetic and environmental factors.
In patients diagnosed with hypertension before age 45, secondary causes should be ruled out, such as kidney disease, endocrine disorders (e.g., thyroid disease, adrenal tumors, oral contraceptives), certain medications (steroids, NSAIDs), pregnancy-related complications, and sleep apnea. Treating the underlying disease can reduce secondary hypertension.
Symptoms of Hypertension
Most patients with hypertension are asymptomatic, which is why it’s called the “silent killer.” However, prolonged high blood pressure may cause:
- Dizziness
- Blurred vision
- Chest tightness
- Nausea
- Fatigue
- Flushing of the face
Note: These symptoms are not always present. In cases of hypertensive crisis (rapidly elevated BP), patients may experience headache, chest pain, or shortness of breath and should seek emergency medical attention immediately.
Diagnosis of Hypertension
The main method for diagnosing hypertension is measuring blood pressure with a cuff in a clinical setting or at home. The doctor will also inquire about medical history and may order blood tests or imaging studies to determine causes, exclude secondary hypertension, and assess potential complications.
Treatment of Hypertension
Treatment focuses on lifestyle modifications and, if necessary, medication. Lifestyle changes include:
If lifestyle changes are insufficient, medications are prescribed. Common antihypertensive drugs include:
- Angiotensin-Converting Enzyme (ACE) inhibitors
- Angiotensin II receptor blockers
- Beta-blockers
- Calcium channel blockers
- Diuretics
- Alpha-blockers
- Vasodilators
Primary hypertension is manageable but not curable. Even if blood pressure temporarily normalizes with medication, do not stop or alter medication without medical advice, as blood pressure can rebound dangerously. Each drug has specific characteristics and side effects; always follow your doctor’s instructions and consult if you experience issues.
Homes Medical Tips: Regular Blood Pressure Monitoring and Record-Keeping
The frequency of blood pressure measurement varies per individual. Usually, measuring a few times a week suffices. During initial diagnosis, medication changes, or dosage adjustments, more frequent checks (e.g., three times daily: morning, noon, evening) may be needed. Patients should record their readings accurately for review during doctor visits.
Choose a relaxed, comfortable time for measurement. Use a chart like the example below:
| Date | Time | Systolic (mmHg) | Diastolic (mmHg) | Pulse (bpm) |
|---|---|---|---|---|
| 28/7 | 9am | 132 | 88 | 68 |
| 8pm | 137 | 79 | 72 |
If readings are higher than usual, stay calm and measure again after resting. Many factors—illness, medications, food, emotions—can temporarily affect BP. If elevated readings persist, seek professional medical advice.
FAQ
Studies suggest 80-90% of hypertension cases are related to genetics. However, having hypertensive parents does not guarantee your own condition. Environmental factors like poor lifestyle, lack of exercise, obesity, excessive salt intake, alcohol, and stress also play significant roles. If parents developed hypertension at a young age, their children are at higher risk.
Usually, hypertension has no obvious symptoms. It is often discovered during health checks or after complications occur. When symptoms do appear, they may include dizziness, blurred vision, headaches, fatigue, and facial flushing.
The target is to keep blood pressure below 130/80 mmHg. If BP is consistently ≥140/90 mmHg, or if other risk factors are present, your doctor may recommend starting medication, especially if lifestyle changes are insufficient after 2-3 months.
Sources: WHO, Department of Health Hong Kong, American Heart Association