Hypertension

Hypertension, also referred to as high blood pressure, HTN or HPN, is a medical condition in which the blood pressure is chronically elevated. In current usage, the word "hypertension"^[ without a qualifier normally refers to arterial hypertension.

Hypertension can be classified either essential (primary) or secondary. Essential hypertension indicates that no specific medical cause can be found to explain a patient's condition. Secondary hypertension indicates that the high blood pressure is a result of (i.e., secondary to) another condition, such as kidney disease or tumours (pheochromocytoma and paraganglioma).

In individuals older than 50 years, hypertension is considered to be present when a person's systolic blood pressure is consistently 140 mm Hg or greater. Beginning at a systolic pressure of 115 and diastolic pressure of 75 (commonly written as 115/75 mm Hg), cardiovascular diseasePrehypertension is defined as blood pressure from 120/80 mm Hg to 139/89 mm Hg. Prehypertension is not a disease category; rather, it is a designation chosen to identify individuals at high risk of developing hypertension.Mayo Clinic specifies blood pressure is "normal if it's below 120/80". Patients with blood pressures over 130/80 mm Hg along with Type 1 or Type 2 diabetes, or kidney disease require further treatment.

(CVD) risk doubles for each increment of 20/10 mmHg. The

Distinguishing primary vs. secondary hypertension

Once the diagnosis of hypertension has been made it is important to attempt to exclude or identify reversible (secondary) causes.

• Over 91% of adult hypertension has no clear cause and is therefore called essential/primary hypertension. Often, it is part of the metabolic "syndrome X" in patients with insulin resistance: it occurs in combination with diabetes mellitus (type 2), combined hyperlipidemia and central obesity.
• Secondary hypertension is more common in preadolescent children, with most cases caused by renal disease. Primary or essential hypertension is more common in adolescents and has multiple risk factors, including obesity and a family history of hypertension.

Investigations commonly performed in newly diagnosed hypertension

Tests are undertaken to identify possible causes of secondary hypertension, and seek evidence for end-organ damage to the heart itself or the eyes (retina) and kidneys. Diabetes and raised cholesterol levels being additional risk factors for the development of cardiovascular disease are also tested for as they will also require management.

Blood tests commonly performed :

• Creatinine (renal function) - to identify both underlying renal disease as a cause of hypertension and conversely hypertension causing onset of kidney damage. Also a baseline for later monitoring the possible side-effects of certain antihypertensive drugs.
• Electrolytes (sodium, potassium)
• Glucose - to identify diabetes mellitus
• Cholesterol

Additional tests often include:

• Testing of urine samples for proteinuria - again to pick up underlying kidney disease or evidence of hypertensive renal damage.
• Electrocardiogram (EKG/ECG) - for evidence of the heart being under strain from working against a high blood pressure. Also may show resulting thickening of the heart muscle (left ventricular hypertrophy) or of the occurrence of previous silent cardiac disease (either subtle electrical conduction disruption or even a myocardial infarction).
• Chest X-ray - again for signs of cardiac enlargement or evidence of cardiac failure.

Prevention

Drug-free Treatment of Hypertension

Lifestyle modification (nonpharmacologic treatment)

• Weight reduction and regular aerobic exercise (e.g., jogging) are recommended as the first steps in treating mild to moderate hypertension. Regular mild exercise improves blood flow and helps to reduce resting heart rate and blood pressure. These steps are highly effective in reducing blood pressure, although drug therapy is still necessary for many patients with moderate or severe hypertension to bring their blood pressure down to a safe level.
• Reducing dietary sugar intake
• Reducing sodium (salt) in the diet may be effective: it decreases blood pressure in about 33 percent of people (see above). Many people choose to use a salt substitute to reduce their salt intake.
• Additional dietary changes beneficial to reducing blood pressure includes the DASH dietdietary approaches to stop hypertension), which is rich in fruits and vegetables and low fat or fat-free dairy foods. This diet is shown effective based on research sponsored by the US National Institutes of Health. In addition, an increase in daily calcium intake has the benefit of increasing dietary potassium, which theoretically can offset the effect of sodium and act on the kidney to decrease blood pressure. This has also been shown to be highly effective in reducing blood pressure. (
• Discontinuing tobacco use and alcohol consumption has been shown to lower blood pressure. The exact mechanisms are not fully understood, but blood pressure (especially systolic) always transiently increases following alcohol and/or nicotine consumption. Besides, abstention from cigarette smoking is important for people with hypertension because it reduces the risk of many dangerous outcomes of hypertension, such as stroke and heart attack. Note that coffee drinking (caffeine ingestion) also increases blood pressure transiently, but does not produce chronic hypertension.
• Reducing stress, for example with relaxation therapy, such as meditation and other mindbody relaxation techniques, by reducing environmental stress such as high sound levels and over-illumination can be an additional method of ameliorating hypertension. Jacobson's Progressive Muscle Relaxation and biofeedback are also used, particularly, device-guided paced breathing, although meta-analysis suggests it is not effective unless combined with other relaxation techniques.

The aim of treatment should be blood pressure control to <140/90 style="text-decoration: underline;"> Each added drug may reduce the systolic blood pressure by 5-10 mmHg, so often multiple drugs are necessary to achieve blood pressure control.

Commonly used drugs :

• ACE inhibitors such as creatine captopril, enalapril, fosinopril (Monopril), lisinoprilquinapril, ramipril (Altace) (Zestril),
• Angiotensin II receptor antagonists: eg, telmisartan (Micardis, Pritor), irbesartanlosartan (Cozaar), valsartan (Diovan), candesartan (Amias) (Avapro),
• Alpha blockers such as prazosin, or terazosin. Doxazosin has been shown to increase risk of heart failure, and to be less effective than a simple diuretic^[29], so is not recommended.
• Beta blockers such as atenolol, labetalol, metoprolol (Lopressor, Toprol-XL), propranolol.
• Calcium channel blockers such as nifedipine (Adalat)^[30] amlodipine (Norvasc), diltiazem, verapamil
• Direct renin inhibitors such as aliskiren (Tekturna)
• Diuretics: eg, bendroflumethiazide, chlortalidone, hydrochlorothiazide (also called HCTZ)
• Combination products (which usually contain HCTZ and one other drug)

Complications

While elevated blood pressure alone is not an illness, it often requires treatment due to its short- and long-term effects on many organs. The risk is increased for:

• Cerebrovascular accident (CVAs or strokes)
• Myocardial infarction (heart attack)
• Hypertensive cardiomyopathy (heart failure due to chronically high blood pressure)
• Hypertensive retinopathy - damage to the retina
• Hypertensive nephropathy - chronic renal failure due to chronically high blood pressure
• Hypertensive encephalopathy - confusion, headache , convulsion due to vasogenic edema in brain due to high blood pressure.