A hypertensive emergency is a medical condition marked by a sudden and severe spike in blood pressure to 180/120 millimeters of mercury (mm Hg) or higher. This sharp increase can lead to damage in the body’s organs. It is a life-threatening event that can result in complications like a heart attack or stroke if not treated promptly.
Differentiating Hypertensive Urgency
The distinction between a hypertensive emergency and urgency is the presence of acute target-organ damage, though both involve blood pressure readings over 180/120 mm Hg. An emergency is diagnosed when this severe elevation causes new or worsening damage to major organs. Hypertensive urgency involves the same high blood pressure levels but without evidence of acute organ injury.
Examples of target-organ damage that characterize an emergency include neurological issues like a stroke, hypertensive encephalopathy (brain dysfunction), or bleeding in the brain. It can also manifest as cardiac events such as a heart attack, acute heart failure with fluid in the lungs (pulmonary edema), or a tear in the body’s main artery, known as an aortic dissection. Other forms of organ damage include acute kidney failure and complications of pregnancy like eclampsia.
While a person with hypertensive urgency may experience symptoms like a headache or shortness of breath, these are not linked to progressive organ damage. An emergency requires immediate hospitalization and intravenous medication to lower blood pressure in a controlled manner. For an urgency, the goal is to reduce blood pressure more gradually over 24 hours, often with oral medications.
Signs and Symptoms
The signs of a hypertensive emergency are directly related to the affected organ system. Neurological symptoms are common and can include a sudden, severe headache, confusion, blurred vision, and seizures. These symptoms may point towards conditions like a stroke or hypertensive encephalopathy.
Cardiovascular signs are also prominent, with severe chest pain potentially signaling a heart attack or aortic dissection. Shortness of breath can indicate the heart is struggling to pump effectively, leading to pulmonary edema. Other symptoms can include nausea and vomiting.
Some signs are more specific to the organ being damaged. For example, changes in vision can be a sign of hypertensive retinopathy, where blood vessels in the eye are damaged. Decreased urine output can be a symptom of acute kidney failure.
Associated Causes and Risk Factors
A hypertensive emergency most often occurs in individuals with chronic hypertension, particularly when the condition is poorly managed or they stop taking prescribed medications. The abrupt cessation of blood pressure medication can also trigger a crisis. Illicit drug use, like with stimulants such as cocaine and amphetamines, is another cause.
Certain medical conditions increase the risk. Chronic kidney disease is a major risk factor, as kidneys help regulate blood pressure. Other cardiovascular conditions like coronary artery disease, congestive heart failure, and a previous stroke also elevate the risk, as can tumors of the adrenal glands.
In pregnant individuals, conditions like preeclampsia and eclampsia are considered hypertensive emergencies. Demographic factors also play a role; the risk is higher in males and increases with age. Lifestyle factors such as obesity and excessive alcohol consumption contribute to the overall risk profile.
Immediate Medical Interventions
Upon arrival at a hospital, a person with a hypertensive emergency will be admitted, often to an intensive care unit (ICU), for continuous monitoring. The primary goal is to lower blood pressure in a controlled and gradual manner. An overly rapid reduction can be dangerous, potentially causing insufficient blood flow to vital organs.
This controlled reduction is achieved using intravenous (IV) medications that have a rapid onset and a short duration of action, allowing for precise and easily adjustable dosing. Commonly used medications include labetalol, nicardipine, and esmolol. The specific choice of drug often depends on the type of organ damage present; for instance, different medications might be prioritized for a patient having a stroke versus one with an aortic dissection.
The typical target for initial treatment is to reduce the mean arterial pressure by no more than 25% within the first hour. If the patient’s condition is stable, the blood pressure is then gradually lowered further over the next several hours.