Understanding High Blood Pressure -- the Basics
What Is High Blood Pressure? continued...
Even so, many people with high blood pressure don't realize they have the condition. Indeed, hypertension is often called "the silent killer" because it rarely causes symptoms, even as it inflicts serious damage to the body. Left untreated, high blood pressure can lead to vision problems, as well as to heart attack, stroke, and other potentially fatal conditions, including kidney failure.
Hypertension may also lead to heart failure, a common but disabling condition that can cause breathing problems. Critically ill patients who have very high blood pressure are said to have malignant hypertension, with a diastolic pressure usually exceeding 120 or a systolic pressure above 180. Malignant hypertension is a dangerous condition that may develop rapidly and cause organ damage quickly. It requires immediate medical attention.
Fortunately, high blood pressure can be controlled effectively. The first step is to have your blood pressure checked regularly.
Who Gets Hypertension?
High blood pressure is more likely in people who:
- Have a family history of high blood pressure, heart disease, or diabetes
- Are African-American
- Are over age 55
- Are overweight
- Are not physically active
- Drink excessively
- Eat foods high in salt
- Use certain medications such as NSAIDs (ibuprofen, aspirin, e.g.), decongestants, and illicit drugs such as cocaine
What Causes High Blood Pressure?
In as many as 95% of reported high blood pressure cases in the U.S., the underlying cause cannot be determined. This type of high blood pressure is called essential hypertension.
Though essential hypertension remains somewhat mysterious, it has been linked to certain risk factors. High blood pressure tends to run in families and is more likely to affect men than women. Age and race also play a role. In the U.S., blacks are twice as likely as whites to have high blood pressure, although the gap begins to narrow around age 44. After age 65, black women have the highest incidence of high blood pressure.
Essential hypertension is also greatly influenced by diet and lifestyle. The link between salt and high blood pressure is especially compelling. People living on the northern islands of Japan eat more salt per capita than anyone else in the world and have the highest incidence of essential hypertension. By contrast, people who add no salt to their food show virtually no traces of essential hypertension.
Many people with high blood pressure are "salt sensitive," meaning that anything more than the minimal bodily need for salt is too much for them and increases their blood pressure. Other factors that have been associated with essential hypertension include obesity; diabetes; stress; insufficient intake of potassium, calcium, and magnesium; lack of physical activity; and chronic alcohol consumption.
When a direct cause for high blood pressure can be identified, the condition is described as secondary hypertension. Among the known causes of secondary hypertension, kidney disease ranks highest. Hypertension can also be triggered by tumors or other abnormalities that cause the adrenal glands (small glands that sit atop the kidneys) to secrete excess amounts of the hormones that elevate blood pressure. Birth control pills -- specifically those containing estrogen -- and pregnancy can boost blood pressure, as can medications that constrict blood vessels.