Arterial hypertensionArterial hypertension, or high blood pressure is a medical condition where the blood pressure is chronically elevated above (currently) 140/90 mm Hg. Persistent hypertension is one of the risk factors for strokes and heart attacks and is a leading cause of kidney failure.
The level of blood pressure regarded as deleterious has been revised down during years of epidemiological studies. A widely quoted and important series of such studies is the Framingham Heart Study carried out in an American town - Framingham, Massachusetts. The results from Framingham and of similar work in Busselton, Western Australia have been widely applied. To the extent that people are similar this seems reasonable, but there are known to be genetic variations in the most effective drugs for particular sub-populations.
Mild hypertension is usually treated by diet, exercise and improved physical fitness. A diet rich in fruits and vegetables and fat-free dairy foods and low in fat and sodium, the so-called DASH diet, has been demonstrated to lower blood pressure in people with hypertension. Dietary sodium (table salt) may be responsible for hypertension in some people. Eating low-salt and salt-free foods will decrease blood pressure in 1/3 of people. Regular mild cardiovascular exercise improves the circulation and bloodflow, and can also help to lower blood pressure. Hypertension is often confused with mental tension, stress and anxiety. While chronic anxiety is associated with poor outcomes in people with hypertension, it alone does not cause it. Furthermore, relaxation therapy and biofeedback do little if anything to control blood pressure.
There are many medications for treating hypertension. In the ALLHAT trial, hydrochlorothiazide was found to be the most effective antihypertensive medication in terms of reduction in risk of heart attacks and strokes. ACE inhibitors and calcium channel blockers were found to have no effect on these outcomes. Results in patients treated with Alpha blockers but not diuretics were found to be definitely less good (heart failure was more likely) and this arm of the trial was terminated early.
For more information on ALLHAT, see http://allhat.sph.uth.tmc.edu/default.htm#study Complications of hypertension include:
- Malignant hypertension
- Hypertensive urgency
- Hypertensive cardiomyopathy
- Hypertensive retinopathy
- Hypertensive nephropathy
- Atrial fibrillation