High BP affects about 65 million adult Americans.¹ Worldwide, hypertension is seen in about 1 billion people and the prevalence hasbeen estimated to increase by more than 29% by the year 2025.² This condition is associated with increased obesity and aging population.Due to the associated morbidity, mortality and economical burden to the society, hypertension remains as a significant public health challenge.

As hypertension rarely causes specific symptoms, it is undetected until an individual’s BP is measured by a physician or until it had caused complications such as stroke or heart attack. The primary goal of treatment is to lower the BP to a normal level through appropriate combination of drugs that achieves this goal.

Recommendations for pharmacologic treatment are based on the presence of symptomatic hypertension, evidence of end-organ damage and unresponsiveness to lifestyle modifications. Drug selection is largely determined by individual’s needs including the presence of any coexisting illness.

Classification of High Blood Pressure

Classification of Hypertension 

Hypertension is classified as primary hypertension and secondary hypertension. Primary or essential hypertension which accounts for more than 90% of cases of hypertension is diagnosed in the absence of an identifiable   

How High Blood Pressure develops
Essentially, Blood pressure is the outcome of cardiac output and peripheral vascular resistance (Blood pressure=cardiac output×peripheral vascular resistance). Therefore, maintenance of a normal BP is dependent on the balance between the cardiac output and peripheral vascular resistance.

• Increased sympathetic nervous system activity.
• Increased production of sodium-retaining hormones and vasoconstrictors.
• Deficiencies of vasodilators such as prostacyclin and nitric oxide.
• Inappropriate or increased renin secretion, resulting in increased production of angiotensin II and aldosterone.
• Genetic predisposition.

Secondary Hypertension
The common identifiable causes of hypertension are the following:

• Chronic kidney disease
• Renovascular disease
• Cushing’s syndrome (hypersecretion of the hormone cortisol)
• Pheochromocytoma (adrenal tumor)
• Drugs such as nonsteroidal antiinflammatory drugs (NSAIDs) and oral contraceptives