Hypertension, or high blood pressure, occurs when the volume and force of blood pushing on the inner walls of the body's blood vessels becomes abnormally high. While aging, pregnancy, certain medical conditions and medications can cause some types of hypertension, most cases of high blood pressure are believed to result fromby a combination of lifestyle and medical factors.
Prehypertension
Prehypertension is defined as having a systolic measurement between 120 and 139 and/or a diastolic pressure between 80 and 89, according to Drugs.com. Physicians consider individuals with prehypertension at risk for developing hypertension and may advise them to take medicine or modify their diet and exercise routines to keep their blood pressure from rising any further.
Primary, or Essential, Hypertension
According to the American Association of Retired Persons website at AARP.org, the vast majority of those with high blood pressure have primary or "essential", hypertension--a type of hypertension whose cause remains unknown. Essential hypertension may result due to a combination of lifestyle factors such as diet, weight and activity level, and medical factors, including genetics, hormones and disease.
Secondary Hypertension
Secondary hypertension results from an underlying health condition or as a side effect of certain medications. According to AARP.org, renal artery stenosis--a condition in which fatty deposits narrow the artery through which blood flows into the kidney--and hormonal conditions such as hyperthyroidism--a condition in which too much thyroid hormone is produced by the thyroid gland--and hyperaldosteronism--a condition caused when the adrenal glands produce excessive amounts of the hormone aldosterone--are common secondary causes of hypertension. Cushing's syndrome--a hormonal disorder caused by abnormally high levels of the hormone cortisol in the bloodstream--can also lead to high blood pressure.
Stress, sleep apnea, certain heart conditions and over-the-counter and prescription medications such as ibuprofen, aspirin, corticosteroids such as prednisone, anabolic steroids, certain antidepressants and pseudoephedrine--a drug commonly found in nasal decongestant and cold medications--can also cause secondary hypertension.
Isolated Systolic Hypertension
Isolated systolic hypertension is characterized by an elevated systolic pressure of at least 160 millimeters of mercury, according to Drugs.com. The most common type of hypertension among the elderly according to AARP.org, isolated systolic hypertension can occur as a byproduct of aging as blood vessels lose their elasticity and become more easily damaged.
Hypertension During Pregnancy
According to eMedTV, preeclampsia is a dangerous type of hypertension that occurs in roughly 4 percent of all pregnancies and proves most common in first pregnancies. Preeclamsia needs to be monitored closely as it can progress to eclampsia--a more severe and persistent form of pregnancy-induced hypertension that can adversely affect the health of the fetus and cause serious complications such as vision problems, seizures or coma in the mother. Pregnancy-induced hypertension usually resolves on its own after delivery; however, mothers may require medication if it persists.
Fluctuating or Situational Hypertension
Some people may develop high blood pressure only in response to stressful situations. For example, "white-coat hypertension" occurs among those whose blood pressure rises only when in a hospital, clinic or doctor's office. According to AARP.org, some individuals have labile hypertension--blood pressure that fluctuates erratically, commonly in response to stress, anxiety or caffeine intake. These fluctuations can become dangerous and should be monitored and treated by a qualified physician.
