Grow Youthful: How to Slow Your Aging and Enjoy Extraordinary Health
Grow Youthful: How to Slow Your Aging and Enjoy Extraordinary Health

Hypertension / high blood pressure

What is hypertension?

Measurement of hypertension

Symptoms of hypertension

Consequences of hypertension

Prevention / remedies / treatment for hypertension

References

What is hypertension?

High blood pressure (arterial hypertension) is a chronic medical condition in which the blood pressure in the arteries is too high. This means that the heart has to work harder than normal to circulate the blood through the arteries around the body.

The resistance in blood vessels has the greatest direct influence on blood pressure. Healthy blood vessels are elastic, and are not scarred or blocked (See atherosclerosis). Other factors include gravity, the condition of the valves in veins, the pumping from contraction of skeletal muscles, and the change in pressure momentarily from standing up. Indirect factors include the general level of health, stress, nutritional factors, drugs, disease and exercise. Sometimes the variations are large.

Hypertension is when arterial pressure is abnormally high, as opposed to hypotension, when it is abnormally low. Low blood pressure can cause a lightheaded feeling, dizziness, weakness or fainting. In extreme cases hypotension can cause shock.

About 25% of all adults in the world suffer from hypertension. (1) In the USA hypertension affected 76 million adults (34% of the population) in 2006. Almost 25% of all adults in the USA take antihypertensive medications. (2) African American adults have among the highest rates of hypertension in the world at 44%. (3) Hypertension is more common in men (though menopause tends to decrease this difference); blacks and native Americans; and those who are economically or socially disadvantaged.

Primary hypertension is when there is no obvious underlying medical cause, and this occurs in 90-95% of cases.

Secondary hypertension (that occurs in the remaining 5-10% of cases) is usually caused by diseases that affect the kidneys, arteries, heart or endocrine system. They include obesity, glucose intolerance, diabetes and thyroid diseases, for example.

Measurement of hypertension

Two metrics are used to measure blood pressure - systolic and diastolic readings. During each heartbeat, there is a high pressure as the heart contracts, and a low reading as the heart relaxes between beats. Normal blood pressure while at rest should be 100-140mmHg systolic and 60-90mmHg diastolic. High blood pressure is said to occur if it is continually at or above 140/90 mmHg.

A resting, healthy adult should have a blood pressure of 120 mmHg (16 kPa) systolic and 80 mmHg (11 kPa) diastolic (written as 120/80 mmHg). This figure of 120/80 can have large individual variations. In children, the normal ranges are lower than for adults, and rise for taller children. 140/90 may be considered normal for older adults, though this is bordering on hypertension. On the other hand, a BP of 90/60 is considered as bordering on hypotension.

The risk of cardiovascular and other diseases increases progressively above 115/75 mmHg. Severely elevated blood pressure (180/ 110) is also known as accelerated or malignant hypertension, or hypertensive emergency or crisis. It increases the risk of symptoms and consequences.

Up to 25% of patients feel stressed when having their blood pressure taken, making the reading higher than it would normally be.

Symptoms of hypertension

Mild or even moderate hypertension is rarely accompanied by any symptoms. Usually it is only identified during a regular check-up or when seeking advice for some other problem.

For those suffering only mildly elevated blood pressure, the following symptoms are more likely to be caused by the associated anxiety than the high blood pressure itself.

Severely elevated blood pressure (malignant hypertension) increases both the risk of the following symptoms, and the consequences.

Consequences of hypertension

Hypertension is a major risk factor for:

Prevention / remedies / treatment for hypertension

References

1. Kearney PM, Whelton M, Reynolds K, Muntner P, Whelton PK, He J. Global burden of hypertension: analysis of worldwide data. 2005, Lancet 365 (9455): 217-23. PMID 15652604.

2. Burt VL, Whelton P, Roccella EJ et al. Prevalence of hypertension in the US adult population. Results from the Third National Health and Nutrition Examination Survey, 1988-1991. March 1995, Hypertension 25 (3): 305-13. PMID 7875754.

3. Lloyd-Jones D, Adams RJ, Brown TM et al. Heart disease and stroke statistics - 2010 update: a report from the American Heart Association. February 2010, Circulation 121 (7): e46-e215. PMID 20019324.