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Hypertension

Hypertension, also known as high blood pressure, is a chronic medical condition in which the blood pressure in the arteries is persistently elevated. It is a major risk factor for cardiovascular diseases, including stroke, heart attack, and heart failure. Hypertension is often referred to as the "silent killer" because it typically has no symptoms until it has caused significant damage to the heart and arteries.

Pathophysiology

Hypertension results from a complex interplay of genetic, environmental, and lifestyle factors. Blood pressure is determined by the amount of blood the heart pumps and the resistance to blood flow in the arteries. When the arteries are narrowed or stiffened, the heart must pump harder to circulate blood, leading to increased blood pressure.

Primary Hypertension

Primary, or essential, hypertension is the most common type, accounting for about 90-95% of cases. It has no identifiable cause but is associated with risk factors such as age, obesity, sedentary lifestyle, high salt intake, and genetic predisposition.

Secondary Hypertension

Secondary hypertension is caused by an underlying condition, such as kidney disease, adrenal gland tumors, or certain medications. It accounts for 5-10% of hypertension cases.

Diagnosis

Hypertension is diagnosed using a sphygmomanometer to measure blood pressure. Blood pressure readings are given in millimeters of mercury (mmHg) and include two numbers: systolic pressure (the pressure when the heart beats) and diastolic pressure (the pressure when the heart rests between beats).

Blood Pressure Categories

• Normal: Systolic < 120 mmHg and Diastolic < 80 mmHg
• Elevated: Systolic 120-129 mmHg and Diastolic < 80 mmHg
• Hypertension Stage 1: Systolic 130-139 mmHg or Diastolic 80-89 mmHg
• Hypertension Stage 2: Systolic ≥ 140 mmHg or Diastolic ≥ 90 mmHg
• Hypertensive Crisis: Systolic > 180 mmHg and/or Diastolic > 120 mmHg

Management

Management of hypertension involves lifestyle modifications and pharmacological treatment.

Lifestyle Modifications

• Diet: A diet low in salt, rich in fruits, vegetables, and whole grains (such as the DASH diet) can help lower blood pressure.
• Exercise: Regular physical activity, such as 150 minutes of moderate aerobic exercise per week, is recommended.
• Weight Loss: Losing weight can significantly reduce blood pressure in overweight individuals.
• Alcohol and Tobacco: Limiting alcohol intake and avoiding tobacco use are important for managing hypertension.

Pharmacological Treatment

Several classes of medications are used to treat hypertension, including:

• Diuretics: Help the kidneys remove sodium and water, reducing blood volume.
• ACE Inhibitors: Relax blood vessels by blocking the formation of a natural chemical that narrows blood vessels.
• Calcium Channel Blockers: Prevent calcium from entering heart and blood vessel muscle cells, leading to relaxed blood vessels.
• Beta-Blockers: Reduce the heart rate and the heart's output of blood.

Complications

If left untreated, hypertension can lead to serious health problems, including:

• Heart Attack: Damage to the arteries can lead to coronary artery disease and heart attacks.
• Stroke: High blood pressure can cause blood vessels in the brain to burst or become blocked.
• Kidney Damage: Hypertension can damage the blood vessels in the kidneys, leading to kidney failure.
• Vision Loss: Damage to the blood vessels in the eyes can lead to vision problems or blindness.

Also see

• Cardiovascular disease
• Stroke
• Heart failure
• Kidney disease
• DASH diet