The degree to which hypertension can be prevented depends on a number of features including: current blood pressure level, changes in end/target organs (retina, kidney, heart - among others), risk factors for cardiovascular diseases and the age at presentation. Unless the presenting patient has very severe hypertension, there should be a relatively prolonged assessment period within which repeated measurements of blood pressure should be taken. Following this, lifestyle advice and non-pharmacological options should be offered to the patient, before any initiation of drug therapy. The process of managing hypertension according the guidelines of the British Hypertension Society suggest that non-pharmacological options should be explored in all patients who are hypertensive or pre-hypertensive. These measures include;
- Weight reduction and regular aerobic exercise (e.g., walking) are recommended as the first steps in treating mild to moderate hypertension. Regular exercise improves blood flow and helps to reduce resting heart rate and blood pressure. Several studies indicate that low intensity exercise may be more effective in lowering blood pressure than higher intensity exercise. 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% of people (see above). Many people use a salt substitute to reduce their salt intake.
- Additional dietary changes beneficial to reducing blood pressure include the DASH diet (dietary approaches to stop hypertension) which is rich in fruits and vegetables and low-fat or fat-free dairy foods. This diet has been shown to be effective based on research sponsored by the National Heart, Lung, and Blood Institute. 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 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.
Unless hypertension is severe, lifestyle changes such as those discussed in the preceding section are strongly recommended before initiation of drug therapy. Adoption of the DASH diet is one example of lifestyle change repeatedly shown to effectively lower mildly-elevated blood pressure. If hypertension is high enough to justify immediate use of medications, lifestyle changes are initiated concomitantly. A series of UK guidelines advocate treatment initiation thresholds and desirable targets to be reached as set out in the following table. Of particular note is that for patients with blood pressures between 140-159/80-99 and without additional factors, that only lifestyle actions and regular blood pressure and risk-factor review is proposed.
|Thresholds for starting treatment ||Group ||Target of treatment |
|>160/100 ||all those with such persisting readings ||<140/90 |
|>140/90 ||If also: Cardiovascular risk >20% per 10 years Or have established cardiovascular disease Or have evidence end organ damage Or chronic kidney disease without high levels albuminuria ||<140/90 |
|>130/80 ||Type 2 Diabetes alone ||<130/80 |
|>135/85 ||Type 1 Diabetes alone ||<130/80 |
|>130/80 ||Type 1 Diabetes with microalbuminuria Or Type 2 Diabetes with kidney, eye or cerebrovascular damage ||<130/80 |
|>130/80 ||chronic kidney disease with high levels albuminuria ||<125/75 |
There are many classes of medications for treating hypertension, together called antihypertensives, which by varying means act by lowering blood pressure. Evidence suggests that reduction of the blood pressure by 56mmHg can decrease the risk of stroke by 40%, of coronary heart disease by 1520%, and reduces the likelihood of dementia, heart failure, and mortality from vascular disease. The aim of treatment should be blood pressure control to <140/90mmHg for most patients, and lower in certain contexts such as diabetes or kidney disease (some medical professionals recommend keeping levels below 120/80mmHg).
Each added drug may reduce the systolic blood pressure by 510mmHg, so often multiple drugs are often necessary to achieve blood pressure control. Commonly used drugs include the typical groups of:
- ACE inhibitors such as captopril, enalapril, fosinopril (Monopril), lisinopril (Zestril), quinapril, ramipril (Altace)
- Angiotensin II receptor antagonists may be used where ACE inhibitors are not tolerated: eg, telmisartan (Micardis, Pritor), irbesartan (Avapro), losartan (Cozaar), valsartan (Diovan), candesartan (Amias), olmesartan (Benicar, Olmetec)
- Calcium channel blockers such as nifedipine (Adalat) amlodipine (Norvasc), diltiazem, verapamil
- Diuretics: eg, bendroflumethiazide, chlortalidone, hydrochlorothiazide (also called HCTZ)
- Additional diuretics such a furosemide or low-dosages of spironolactone
- 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.
- Beta blockers such as atenolol, labetalol, metoprolol (Lopressor, Toprol-XL), propranolol. Whilst once first line agents, now less directly used for this in the United Kingdom due to the risk of diabetes.
- Direct renin inhibitors such as aliskiren (Tekturna)
- Combination products (which usually contain HCTZ and one other drug). The advantage of fixed combinations resides in the fact that they increase compliance with treatment by reducing the number of pills taken by the patients. A fixed combination of the ACE inhibitor perindopril and the calcium channel blocker amlodipine, recently been proved to be very effective even in patients with additional impaired glucose tolerance and in patients with the metabolic syndrome.
- Cerebrovascular accident (CVAs or strokes)[
- Myocardial infarction (heart attack
- Hypertensive cardiomyopathy (heart failure due to chronically high blood pressure)[
- Left ventricular hypertrophy - thickening of the myocardium (muscle) of the left ventricle of the heart.[
- Hypertensive retinopathy - damage to the retina
- Hypertensive nephropathy
- Other additionally used groups include:
- Finally several agents may be given simultaneously:
] Choice of initial medication
Unless the blood pressure is severely elevated, consensus guidelines call for medically-supervised lifestyle changes and observation before recommending initiation of drug therapy. All drug treatments have side effects, and while the evidence of benefit at higher blood pressures is overwhelming, drug trials to lower moderately-elevated blood pressure have failed to reduce overall death rates. If lifestyle changes are ineffective or the presenting blood pressure is critical, then drug therapy is initiated, often requiring more than one agent to effectively lower hypertension. Which type of many medications should be used initially for hypertension has been the subject of several large studies and various national guidelines. The largest study, Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), concluded that thiazide-type diuretics are better and cheaper than other major classes of drugs at preventing cardiovascular disease, and should be preferred as the starting drug. ALLHAT used the thiazide diuretic chlorthalidone.
(ALLHAT showed that doxazosin, an alpha-adrenergic receptor blocker, had a higher incidence of heart failure events, and the doxazosin arm of the study was stopped.) A subsequent smaller study (ANBP2) did not show the slight advantages in thiazide diuretic outcomes observed in the ALLHAT study, and actually showed slightly better outcomes for ACE-inhibitors in older white male patients.
Thiazide diuretics are effective, recommended as the best first-line drug for hypertension by many experts, and are much more affordable than other therapies, yet they are not prescribed as often as some newer drugs. Hydrochlorothiazide is perhaps the safest and most inexpensive agent commonly used in this class and is very frequently combined with other agents in a single pill. Doses in excess of 25 milligrams per day of this agent incur an unacceptable risk of low potassium or Hypokalemia. Patients with an exaggerated hypokalemic response to a low dose of a thiazide diuretic should be suspected to have Hyperaldosteronism, a common cause of secondary hypertension. Other drugs have a role in treating hypertension. Adverse effects of thiazide diuretics include hypercholesterolemia, and impaired glucose tolerance with increased risk of developing Diabetes mellitus type 2. The thiazide diuretics also deplete circulating potassium unless combined with a potassium-sparing diuretic or supplemental potassium. Some authors have challenged thiazides as first line treatment.[
However as the Merck Manual of Geriatrics notes, "thiazide-type diuretics are especially safe and effective in the elderly."
Current UK guidelines suggest starting patients over the age of 55 years and all those of African/Afrocaribbean ethnicity firstly on calcium channel blockers or thiazide diuretics, whilst younger patients of other ethnic groups should be started on ACE-inhibitors. Subsequently if dual therapy is required to use ACE-inhibitor in combination with either a calcium channel blocker or a (thiazide) diuretic. Triple therapy is then of all three groups and should the need arise then to add in a fourth agent, to consider either a further diuretic (eg spironolactone or furosemide), an alpha-blocker or a beta-blocker.
Prior to the demotion of beta-blockers as first line agents, the UK sequence of combination therapy used the first letter of the drug classes and was known as the "ABCD rule".
- It is based upon several factors including genetics, dietary habits, and overall lifestyle choices. If individuals conscious of their condition take the necessary preventive measures to lower their blood pressure, they are more likely to have a much better outcome than those who do not.
- Main article: Complications of hypertension Hypertension is a risk factor for all clinical manifestations of atherosclerosis since it is a risk factor for atherosclerosis itself.It is an independent predisposing factor for heart failure,coronary artery disease,] stroke, renal disease, and peripheral arterial disease.] it is the most important risk factor for cardiovascular morbidity and mortality, in industrialized countries. The risk is increased for:
- - chronic renal failure due to chronically high blood pressure "benign nephrosclerosis".
- Hypertensive encephalopathy - confusion, headahe, convulsion due to vasogenic edema in brain due to high blood pressure.