Stress can elevate blood pressure. For this reason, some people whose blood pressure is usually normal can become hypertensive in the doctor’s office. This phenomenon is dubbed white-coat hypertension. In the past, doctors often dismissed these elevated readings as a reflection of the temporary anxiety many people experience at the clinic or hospital. But now some experts think white-coat hypertension is worth investigating because it might shed light on how stress influences blood pressure.
People who are habitually affected by stress — whether from losing a job, feeling pressure at work, or simply getting stuck in traffic — may develop temporary or longer-lasting hypertension that could inflict some of the same damage as full-time hypertension.
By figuring out how these people’s blood pressure varies throughout the day, doctors can determine how best to treat them — if at all.
To get this information, patients take a portable device home with them and check their blood pressure periodically over the course of a week or two. Another option is a blood pressure monitor and cuff that you wear for 24 hours. The device automatically takes a blood pressure reading every 15–30 minutes while you go about your daily activities.
Labile means ever-changing, and in labile hypertension, blood pressure fluctuates far more than usual. Your blood pressure might soar from 119/76 mm Hg at 10 a.m. to 170/104 mm Hg at 4 p.m. These fluctuations can spring from a variety of sources, such as too much caffeine, anxiety attacks, or stress overload. Whatever the cause, these transient episodes of hypertension can be dangerous and should be treated. As with white-coat hypertension, home blood pressure monitoring over a 24-hour period helps determine the best treatment strategy. You’re most likely to experience labile hypertension when you are in transition from normal to high blood pressure. Its duration can range from a few weeks to many years.
Hypertension is often treated by adopting healthier habits and taking drugs to lower blood pressure, called antihypertensives. The first drug prescribed, however, doesn’t always work. Your doctor may have to increase the dose, prescribe an additional drug, or substitute a different drug. Sometimes, though, your blood pressure remains persistently elevated in spite of these efforts.
In some instances, resistant hypertension results from drug interactions. For example, antihypertensive drugs may lose their effectiveness if you’re also taking certain antidepressants or even some over-the-counter drugs, such as pain relievers, cold preparations, and diet aids. Caffeine and excessive alcohol and licorice (either as candy or as found in some chewing tobaccos) intake can also contribute to persistently high blood pressure. Other causes include panic attacks, chronic pain, sleep apnea, fluid retention, kidney damage, weight gain, and inflammatory artery disease (arteritis).
Give your doctor as much information as possible about the medications you take, the foods and drinks you consume, and any conditions you may have. There are often simple ways to avoid the interactions that render blood pressure medications ineffective.
Though rare, malignant hypertension is the most ominous form of high blood pressure. It’s marked by an unusually sudden rise in blood pressure to dangerous levels, often with the diastolic reading reaching 130 mm Hg or higher. However, it may also occur at lower, seemingly more normal blood pressure levels if the rise is particularly abrupt. Unlike other kinds of hypertension, it’s usually accompanied by dramatic symptoms such as severe headache, shortness of breath, chest pain, nausea and vomiting, blurred vision or even blindness, seizures, and loss of consciousness.
Malignant hypertension is a medical emergency. It places people at immediate risk for heart attack, stroke, heart failure, permanent kidney damage, and bleeding in the brain. Anyone who develops the condition must be hospitalized immediately.
Malignant hypertension develops in less than 1% of people who already have high blood pressure. In rare cases, the appearance of malignant hypertension is the first sign that a person has high blood pressure. While the cause of this condition is unknown, you should never stop taking antihypertensives without your doctor’s supervision. Doing so might cause a precipitous increase in your blood pressure.
Hypertension during pregnancy
Pre-eclampsia, or hypertension during pregnancy, may appear as early as the 20th week of pregnancy and occasionally as late as one week after delivery. Occurring in about 5%–8% of all pregnancies, it’s most common among women experiencing their first pregnancy and women who already have high blood pressure. Most cases of hypertension that develop during pregnancy disappear soon after the child’s birth. Hypertension that persists is called pregnancy-induced hypertension.
The cause of pre-eclampsia is unknown. Signs of pre-eclampsia include swelling of the hands and face, blood-clotting abnormalities, and protein in the urine. For most women, pre-eclampsia never proceeds beyond the mild stage. For some women, though, the disease develops rapidly, moving from mild to severe in a matter of weeks or sometimes days. Doctors usually recommend bed rest. But if the problem remains or worsens, hospitalization and antihypertensive medications are often necessary to prevent pre-eclampsia from progressing to eclampsia, a serious medical condition. Eclampsia can cause dangerously high blood pressure, seizure, coma, and even the death of the mother, the fetus, or both. Since eclampsia frequently disappears once the baby is born, doctors often induce labor. They may also prescribe anticonvulsant medications. If the woman still has hypertension after giving birth, she may need medication. Little is known about the effects of antihypertensive agents in breast milk, however, so breast-fed infants must be closely monitored.
Figure 2. Pregnant woman walking.
In most cases, high blood pressure that develops during pregnancy disappears once the baby is born.