High blood pressure
About 1 in 3 adults in the United States has been diagnosed with HBP (high blood pressure), also known as hypertension. Hypertension is called “the silent killer” because symptoms may not be present but cause serious complications, especially if the condition goes untreated for a long time. For example, high blood pressure can cause life-threatening illnesses such as kidney problems, stroke, heart failure or heart attacks and even blindness.
What is blood pressure?
The cells of the body need oxygen and nutrients to survive. The cardiovascular system delivers oxygen and nutrients to all parts of the body through the blood which the heart pumps through blood vessels. The blood vessels that carry fresh blood from the heart to the body are called arteries. Blood pressure is the measure of the force (the strength) of blood as it presses against the walls of the arteries.
Blood pressure is measured in systolic and diastolic units. Systolic blood pressure measures the force of a heart beat while pumping blood. Diastolic blood pressure measures the pressure when the heart is at rest between beats. Doctors most often record blood pressure numbers with the systolic number above or before the diastolic, such as 120/80 mmHg (mmHg = millimeters of mercury). Blood pressure varies and commonly differs by 10 or 20 units when measured at different time intervals, even minutes apart. For example, exercise or emotional stress can increase blood pressure.
What is hypertension?
Increased blood pressure allows more blood to be pumped to the body to help the body cope with increased activity or stress. This type of variation in blood pressure is normal. However, hypertension occurs when the pressure of blood pushing against the walls of the arteries rises and stays high over time. This type of high blood pressure that remains high for long periods of time can damage the body in many ways and required medical treatment.
Types of hypertension
Essential hypertension – This form of hypertension is also called primary or idiopathic hypertension because doctors cannot identify a specific cause for increased blood pressure.
Pregnancy-induced hypertension (PIH) – PIH is also known as toxemia or preeclampsia and is characterized by a blood pressure reading higher than 140/90 mm Hg, taken in two separate readings over an interval of more than 6 hours and accompanied by 300 mg of proteins in 24-hour urine sample. This condition is also accompanied with edema and damage to the maternal endotholium, liver or kidneys. Preeclampsia precedes eclampsia, which is an episode of increased body pressure, loss of consciousness and convulsions. Eclampsia is fatal, and can occur up until the baby is born.
Isolated systolic hypertension (ISH) – This is the most common form of HBP diagnosed in older adults. ISH occurs when only systolic blood pressure (the top number) is high.
Labile hypertension – Labile hypertension is a type of variable blood pressure that frequently fluctuates between normal and abnormal during the course of a day, often within only a few minutes.
Malignant hypertension –This type of hypertension is severe and dangerous, characterized by a sudden rise in blood pressure to very high levels, often accompanied by headache, blurred vision, and seizures.
Pre-hypertension - Blood pressure in the 120–139/80–89 mmHg range.
Resistant hypertension - Blood pressure that remains chronically high despite the use of medications and lifestyle changes.
Secondary hypertension – High blood pressure that is caused by an identifiable, secondary problem in the body such as alcohol or drug abuse, kidney disorders, or medications.
White coat hypertension – This type of high blood pressure is characterized by a temporary rise in blood pressure only in a doctor's office.
Is high blood pressure common? Who is most at risk of hypertension? And do doctors know what causes it? Click here for more information on risk factors and high blood pressure causes now.