Hypertension

What is Hypertension?

Hypertension is an intermittent or sustained elevation of diastolic or systolic blood pressure. Serial blood pressure measurements greater than 1 40/90 mm Hg in people under age 50 or greater than 150/95 mm Hg in those over age 50 confirm hypertension.

Aside from characteristic high blood pressure, hypertension is classified according to its cause, severity, and type. The two major types are essential (also called primary or idiopathic) hypertension. the most common (90% to 95% of cases), and secondary hypertension, which results from renal disease or another identifiable cause. Malignant hypertension is a severe, fulminant form of hypertension that commonly arises from both types. Blacks are twice as likely as whites to be affected; if untreated, hypertension carries a high mortality.

Essential hypertension usually begins insidiously as a benign disease, slowly progressing to an accelerated or malignant state. If untreated, even mild hypertension can cause significant complications and a high mortality. In many cases, however, treatment with stepped care offers patients an improved prognosis.

Causes of Hypertension

The cause of essential hypertension is unknown. Family history, race, stress, obesity, a diet high in sodium or saturated fat, use of tobacco or oral contraceptives, excess alcohol intake, sedentary lifestyle, and aging have all been studied to determine their role in the development of hypertension.

Secondary hypertension may result from renovascular disease; renal parenchymal disease; pheochromocytoma; primary hyperaldosteronism; Cushing's syndrome; diabetes mellitus; dysfunction of the thyroid, pituitary, or parathyroid gland; coarctation of the aorta; pregnancy; and neurologic disorders. Use of oral contraceptives may be the most common cause of secondary hypertension, probably because these drugs activate the renin-angiotensinaldosterone system. Other medications contributing to secondary hypertension include glucocorticoids, mineralocorticoids, sympathomimetics, cyclosporine, cocaine, and epoetin alfa.

Signs & Symptoms of Hypertension

One of the big problems with high blood pressure is that it hardly ever causes symptoms.

This means it may go unnoticed until it causes one of its later complications such as a stroke or heart attack.

Despite the popularity of such ideas, nosebleeds and ruddy complexions are hardly ever caused by high blood pressure.

Severe hypertension can cause symptoms such as:

• headache
• sleepiness
• confusion
• coma.

Diagnostic Tests

Hypertension may be suspected when the blood pressure is high at any single measurement. It is confirmed through blood pressure measurements that are repeated over time. Blood pressure consistently elevated over 140 systolic or 90 diastolic is called hypertension. Your doctor will look for signs of complications to your heart, kidneys, eyes, and other organs in your body.

Systolic blood pressure consistently between 130 and 139 or diastolic blood pressure consistently between 80 and 89 is called pre-hypertension. Your doctor will recommend and encourage lifestyle changes including weight loss, exercise, and nutritional changes.

Tests for suspected causes and complications may be performed. These are guided by the symptoms presented, history, and results of examination.

Treatment

Although essential hypertension has no cure, drugs and modifications in diet and lifestyle can control it. Generally, nondrug treatment such as lifestyle modification, is tried first, especially in early, mild cases. If this is ineffective, treatment progresses in a stepwise manner to include various types of antihypertensives. This stepped-care approach may need modification. For instance, most blacks respond poorly to betaadrenergic blocking agents; however, for unclear reasons, they respond well to a combination of a diuretic and an angiotensin-converting enzyme inhibitor. Many elderly patients can be treated with diuretics alone.

Treatment for a patient with secondary hypertension includes correcting the underlying cause and controlling hypertensive effects.

Severely elevated blood pressure (hypertensive crisis) may be refractory to medications and may be fatal.

Hypertensive emergencies require parenteral administration of a vasodilator or an adrenergic inhibitor or oral administration of a selected drug (such as nifedipine, captopril, cIonidine, or labetalol), to rapidly reduce blood pressure.

How is high blood pressure controlled?

Many people can control high blood pressure by:

• choosing foods that are low in sodium (salt).
• choosing foods low in calories and fat.
• choosing foods high in starch and fiber.
• maintaining a healthy weight, or losing weight if overweight.
• limiting serving sizes.
• increasing physical activity.
• practicing moderation if consuming alcoholic beverages.

However, other people must take daily medication to control hypertension. People with hypertension should routinely have their blood pressure checked and be under the care of a physician.

Always consult your physician for more information.