Wikipedia:VideoWiki/Hypertension

Overview
Hypertension, also known as high blood pressure, is a long-term medical condition where the blood pressure in the arteries is chronically elevated.



Epidemiology
High blood pressure is very common, and affects between 16 and 37% of the population. In 2010, it was a factor in 9.4 million deaths globally.



Symptoms and risks
High blood pressure typically does not show any symptoms, but is a major risk factor for many life threatening conditions, including coronary artery disease, stroke, heart failure, atrial fibrillation, peripheral vascular disease, vision loss, chronic kidney disease, and dementia.



Classification
High blood pressure is classified as either primary, or secondary hypertension. Primary high blood pressure is also known as essential hypertension.



Causes
Roughly 90 to 95% of people with high blood pressure, have the primary type. This is high blood pressure caused by nonspecific lifestyle, and genetic factors.



Most common causes
Lifestyle factors that increase the risk of primary hypertension include smoking, being overweight, too much salt in the diet, and excessive alcohol use.



Less common causes
The remaining 5 to 10% of cases are secondary hypertension, where an identifiable cause can be found, such as the use of birth control pills, chronic kidney disease, narrowing of the arteries to the kidneys, or an endocrine disorder like hyperthyroidism.



Diagnosis
Blood pressure is expressed by two measurements. The systolic number, which is the maximum pressure, and the diastolic number, which is the minimum pressure.



Typical reading
For instance, a blood pressure of 120 over 70 would be normal, in most people when they are at rest.



Normal values
For most adults, when they are resting, a normal maximum (or systolic) blood pressure is between 100 and 130 mmHg, and the minimum (or diastolic) pressure is between 60 and 80 mmHg.



High blood pressure values
A high blood pressure is present when the resting blood pressure is persistently at, or above, 130 over 80, or 140 over 90 mmHg. It is important to realize, children have much different numbers that depend on their age, and size.



Ambulatory blood pressure monitoring
Measuring the blood pressure outside of an office, over a 24 hour period, appears to be more accurate than office-based blood pressure measurement.



Pregnancy
Hypertension occurs in approximately 8 to 10% of pregnancies. This is called gestational hypertension. Two blood pressure measurements, six hours apart, of greater than 140 over 90 mmHg, are diagnostic of hypertension in pregnancy, and should be immediately addressed.



Treatment of moderate hypertension
Research is clear that the treatment of moderately high blood pressure (defined as more than 160 over 100 mmHg), is associated with an improved life expectancy.



Low to moderate blood pressure
The research is less clear on the effect of treatment of blood pressure between the ranges of 130 and 160 mmHg systolic, and 80 to 100 mmHg diastolic. Some reviews find benefit, and others do not.



Effect of lifestyle
Lifestyle changes and medications can lower blood pressure, and decrease the risk of health complications.



Lifestyle changes
Lifestyle changes include weight loss, physical exercise, decreased salt intake, reducing alcohol intake, and a healthy diet.



Treatment with medication
If lifestyle changes are not sufficient, then blood pressure medications are used. Up to three different medications can control hypertension, in 90% of people.