© FatCamera | GettyImages

When you consider blood pressure, it’s important to keep in mind that not all hypertension is the same. Medical experts recognize several types of high blood pressure, each with different etiologies.

Essential Hypertension

Accounting for about 90 percent of all high blood pressure, essential, or primary, hypertension has no single identifiable cause. Rather, it may result from a number of contributing risk factors, such as obesity, a high-sodium diet, older age, and a family history of high blood pressure.

It’s not essential hypertension that is heterogenous (diverse); it’s the causes of hypertension that are heterogenous, meaning that the causal factors that lead to this condition vary from patient to patient.

Secondary Hypertension

Secondary hypertension is high blood pressure that is attributable to a medical condition or other specific cause. Secondary hypertension may develop more rapidly than—and, in some instances, coexist with—essential hypertension. Sometimes, treating or preventing these secondary causes may help you manage your blood pressure more effectively:

• Kidney damage
• Sleep apnea
• Primary aldosteronism
• Narrowing, or coarctation, of the aorta
• Thyroid disease
• Cushing’s syndrome
• Pheochromocytoma
• Chronic alcohol use or abuse

In addition, an array of prescription and OTC medications can cause secondary hypertension, including NSAIDs; corticosteroid drugs; certain antidepressants; OTC allergy medications containing decongestants like pseudoephedrine; and birth control pills. Similarly, certain herbal supplements, such as licorice root, ephedra, and guarana, can cause blood pressure elevations.

Resistant Hypertension

If you try to do all the right things for your health, but your blood pressure remains high despite anti-hypertensive treatment, you might be one of the 12 to 15 percent of people with high blood pressure who have resistant hypertension.

You have resistant hypertension if your blood pressure remains at 130/80 mmHg or higher despite optimal doses of at least three blood pressure medications, or if you need four or more drugs to control your blood pressure. It may mean simply that your blood pressure is difficult to control, but in some instances an underlying medical condition or other secondary cause may be to blame.

The White-Coat Effect and Masked Hypertension

Few people enjoy going to see the doctor, so it’s only natural to feel anxious while you’re there. Couple that with any emotional stress as a result of bad traffic and tardiness, and you might find that your blood pressure is high when your doctor measures it.

Instead, you may be experiencing the “white-coat” effect, which occurs when your blood pressure is elevated only when measured in your doctor’s office or another clinical setting. By some estimates, 15 to 30 percent of people with blood pressure elevations measured in a doctor’s office have white-coat hypertension, named because of the white coats many health-care professionals wear.

On the flip side of the white-coat phenomenon is masked hypertension, or blood pressure readings that are normal in the doctor’s office but high outside the doctor’s office, which can also make diagnosing hypertension more difficult.

Malignant Hypertension and Hypertensive Crises

While essential hypertension typically develops gradually over time, malignant hypertension is a medical emergency characterized by a rapid, severe, and dangerous rise in blood pressure. The condition is relatively rare, occurring more commonly in younger people, particularly African-American men, as well as people with kidney disease, renal artery stenosis, systemic lupus erythematosus, and women with preeclampsia.

Malignant hypertension can lead to a hypertensive crisis, when systolic blood pressure reaches 180 mmHg or higher or diastolic pressure rises to 120 mmHg or higher. When this situation occurs, blood pressure must be lowered within minutes to hours, or else life-threatening complications may occur.

A very high blood pressure that causes symptoms of target organ damage is known as a hypertensive emergency. People with a very high blood pressure without these serious symptoms or signs of organ damage have hypertensive urgency.

Pregnancy-Induced Hypertension

An estimated 3 to 5 percent of pregnant women may develop high blood pressure. The mildest form, gestational hypertension, does not cause symptoms and usually poses no risk to the mother or the fetus.

However, as many as a quarter of women with gestational hypertension progress to preeclampsia, according to the NIH. This condition is characterized by high blood pressure and protein in the urine, along with symptoms such as increased swelling of the hands, face, or eyes, and sudden weight gain.

In about three-quarters of cases, preeclampsia is mild, the NIH notes, but the disorder can worsen from mild to severe in as quickly as a few days. Severe preeclampsia may cause persistent headache, breathing problems, abdominal pain, vision changes, reduced urination, and nausea or vomiting. Sometimes, it can cause loss of pregnancy, pre-term delivery, organ failure, or stroke. If it affects the brain enough, it can trigger seizures or coma—a condition known as eclampsia. These most severe complications can potentially lead to the death of the mother and/or the fetus.

Labile Hypertension

This term sometimes is used to describe hypertension characterized by wide fluctuations in blood pressure readings. However, the clinical significance of labile hypertension remains controversial: Some experts view it as a legitimate medical phenomenon, while others consider it an unnecessary or inappropriate diagnosis because everyone experiences some blood pressure variability to meet the body’s changing demands.

Pulmonary Hypertension

Pulmonary hypertension occurs when blood pressure in the lungs becomes elevated due to a number of potential causes, such as narrowing of blood vessels in the lungs, or problems with the left side of the heart, like mitral valve disease or prolonged high blood pressure. Pulmonary hypertension can be associated with conditions such as COPD, sleep apnea, interstitial lung disease, blood-clotting problems, and congenital heart disease.

Like other forms of high blood pressure, pulmonary hypertension may develop gradually and not produce any warning signs. Possible symptoms of the disease include shortness of breath, chest pain, fatigue, and rapid heartbeat.

To learn about high blood pressure symptoms, risk factors and treatment, purchase Managing Your Blood Pressure at www.UniversityHealthNews.com.