Blood pressure (high)

Overview
High blood pressure, medically termed hypertension, is a chronic medical condition in which the force of the blood against the arterial walls is persistently elevated. Normal blood pressure is generally considered to be around 120/80 mmHg. Hypertension is diagnosed when blood pressure is consistently 140/90 mmHg or higher. It is one of the most common cardiovascular conditions worldwide and a major risk factor for stroke, heart attack, kidney disease, and heart failure.

Hypertension is often called the “silent killer” because it may not cause noticeable symptoms until significant organ damage occurs.

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Types of Hypertension

1. Primary (Essential) Hypertension

   • Accounts for around 90–95% of cases.

   • Develops gradually over many years.

   • Exact cause is unknown but linked to lifestyle, genetics, and aging.

2. Secondary Hypertension

   • Accounts for 5–10% of cases.

   • Caused by an identifiable underlying condition such as kidney disease, hormonal disorders (e.g., Cushing’s syndrome, hyperthyroidism), sleep apnea, or use of certain medications (e.g., corticosteroids, oral contraceptives).

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Causes and Risk Factors

• Genetics: Family history of hypertension.

• Age: Risk increases with age due to vascular stiffening.

• Lifestyle factors:

  • High salt intake.

  • Obesity and overweight.

  • Lack of physical activity.

  • Excess alcohol consumption.

  • Smoking.

• Medical conditions:

  • Diabetes mellitus.

  • Chronic kidney disease.

  • Sleep apnea.

• Stress: Prolonged psychological stress contributes to sustained high blood pressure.

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Symptoms

Hypertension is usually asymptomatic, but when present, symptoms may include:

• Headaches (especially morning headaches).

• Dizziness.

• Blurred vision.

• Shortness of breath.

• Nosebleeds (in severe cases).

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Complications of Untreated Hypertension

Persistent uncontrolled hypertension can damage blood vessels and vital organs, leading to:

• Stroke (ischemic or hemorrhagic).

• Myocardial infarction (heart attack).

• Heart failure due to increased cardiac workload.

• Chronic kidney disease and eventual kidney failure.

• Aneurysms due to weakened blood vessels.

• Retinopathy leading to vision problems.

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Diagnosis

• Blood Pressure Measurement: At least two or more readings on separate occasions.

• Ambulatory Blood Pressure Monitoring (ABPM): 24-hour monitoring to confirm diagnosis.

• Home Blood Pressure Monitoring (HBPM): Useful for ruling out white-coat hypertension.

• Laboratory and Imaging Tests:

  • Urinalysis (to check for protein/kidney function).

  • Blood tests (glucose, cholesterol, electrolytes, creatinine).

  • ECG (to detect cardiac changes).

  • Echocardiogram (in some cases).

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Classification of Blood Pressure in Adults

• Normal: <120/80 mmHg.

• Elevated: 120–129/<80 mmHg.

• Hypertension Stage 1: 130–139/80–89 mmHg.

• Hypertension Stage 2: ≥140/90 mmHg.

• Hypertensive crisis: >180/120 mmHg (medical emergency).

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Management and Treatment

Treatment aims to reduce cardiovascular risk by lowering blood pressure to target levels, generally <130/80 mmHg (in most patients, especially those with diabetes or kidney disease).

1. Lifestyle Modifications

• Diet:

  • Reduce salt intake (<5 g/day).

  • Adopt the DASH diet (Dietary Approaches to Stop Hypertension), rich in fruits, vegetables, whole grains, lean proteins, and low-fat dairy.

• Weight reduction: Maintain a healthy BMI (18.5–24.9).

• Physical activity: At least 150 minutes of moderate aerobic activity weekly.

• Limit alcohol: ≤2 drinks/day for men, ≤1 for women.

• Quit smoking: Reduces cardiovascular risk.

• Stress management: Mindfulness, relaxation techniques.

2. Pharmacological Treatment

If lifestyle changes are insufficient, or if the patient has stage 2 hypertension or associated risk factors, medications are initiated.

First-line medications (generic names and usual doses):

• Thiazide diuretics:

  • Hydrochlorothiazide 12.5–25 mg once daily.

  • Chlorthalidone 12.5–25 mg once daily.

• ACE inhibitors:

  • Enalapril 5–20 mg daily.

  • Lisinopril 10–40 mg daily.

• Angiotensin II receptor blockers (ARBs):

  • Losartan 50–100 mg daily.

  • Valsartan 80–320 mg daily.

• Calcium channel blockers (CCBs):

  • Amlodipine 5–10 mg once daily.

  • Diltiazem 120–360 mg daily.

• Beta-blockers (not first-line unless compelling indications like heart disease):

  • Atenolol 25–100 mg daily.

  • Metoprolol 50–200 mg daily.

Second-line or add-on drugs (for resistant hypertension):

• Aldosterone antagonists: Spironolactone 25–50 mg daily.

• Alpha-blockers: Doxazosin 1–16 mg daily.

• Central alpha-agonists: Clonidine 0.1–0.3 mg twice daily.

• Direct vasodilators: Hydralazine 25–100 mg three times daily.

3. Hypertensive Emergency Management

• Requires intravenous medications and hospitalization.

• Commonly used agents:

  • Nitroprusside: IV infusion titrated to effect.

  • Labetalol: IV bolus 20 mg over 2 minutes, repeat or infuse as needed.

  • Nicardipine: IV infusion starting at 5 mg/hour.

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Monitoring and Follow-Up

• Regular blood pressure checks (every 1–3 months until controlled).

• Monitor electrolytes and kidney function if on diuretics or ACE inhibitors/ARBs.

• Long-term follow-up to assess adherence and complications.

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Prognosis

With early diagnosis, lifestyle modification, and adherence to treatment, hypertension can be well-controlled, significantly reducing the risk of stroke, heart disease, and premature death. However, uncontrolled hypertension leads to progressive damage to organs, reducing life expectancy.