A sudden, severe increase in blood pressure is known as a hypertensive crisis, which occurs when readings rise to 180/120 mm Hg or higher. These events are categorized into two distinct types based on their immediate impact on the body. Understanding the difference is important because they require different medical responses and treatment approaches. The primary distinction lies in whether the elevated pressure is actively causing damage to the body’s major organs.
Defining Hypertensive Urgency
A hypertensive urgency is characterized by severely elevated blood pressure but without any accompanying signs of new or worsening damage to the body’s organs. This condition is serious and requires medical attention, but it is not an immediate, life-threatening event. The body, while under significant strain from the pressure, is not showing evidence of acute failure in its systems.
Patients experiencing hypertensive urgency may be asymptomatic, meaning they feel no different despite the high reading. In other cases, they might experience symptoms such as a severe headache, significant anxiety, shortness of breath, or a nosebleed. The goal of treatment is to lower the blood pressure steadily over 24 to 48 hours using oral medications.
The absence of “end-organ damage” is the defining feature of hypertensive urgency. Physicians will confirm the diagnosis by taking a history and performing a physical exam focused on neurological, cardiac, and renal function to rule out an emergency.
Defining Hypertensive Emergency
A hypertensive emergency is defined by severely elevated blood pressure and is distinguished by the presence of acute and progressive end-organ damage. The extreme pressure is actively causing injury to one or more of the body’s major organ systems, making it a life-threatening medical event that requires immediate treatment.
End-organ damage refers to the functional and structural harm inflicted upon organs like the brain, heart, kidneys, and eyes. When the brain is affected, a person might experience symptoms of hypertensive encephalopathy, including a severe headache, confusion, nausea, vomiting, or seizures. Other neurological signs can mirror those of a stroke, such as sudden blurred vision, facial drooping, or weakness on one side of the body.
When the cardiovascular system is the site of injury, symptoms can include chest pain indicative of a heart attack or severe shortness of breath, which can signal acute pulmonary edema. The kidneys can also be damaged, leading to acute renal failure, which may present as a significant decrease in urine output. Damage to the blood vessels in the eyes, known as retinopathy, can cause vision changes or loss.
Appropriate Medical Response
The correct medical response depends on whether the situation is a hypertensive urgency or an emergency. For a hypertensive urgency, the recommended course of action is to seek prompt medical attention, but it does not require a trip to the emergency room. Contacting a primary care physician or visiting an urgent care clinic is sufficient. The treatment goal is a gradual reduction of blood pressure over 24 to 48 hours, accomplished with oral medications. Rushing to lower the pressure too quickly can be harmful, potentially causing insufficient blood flow to the brain.
A hypertensive emergency demands immediate intervention. Anyone experiencing the symptoms of end-organ damage should have 911 called on their behalf. This condition is treated in a hospital setting, within an intensive care unit (ICU).
In the hospital, intravenous (IV) medications are administered to lower blood pressure more rapidly, but in a highly controlled manner. The objective is to reduce the mean arterial pressure by about 10-20% in the first hour and by another 5-15% over the next 23 hours. This monitored reduction helps prevent further organ damage without causing ischemic injury to the brain or heart.
Underlying Causes of Hypertensive Crises
Several factors can trigger a hypertensive crisis, and it is often related to pre-existing high blood pressure. The most common cause is a patient with known hypertension suddenly stopping or not taking their prescribed medications. This interruption can cause a rebound effect, leading to a sharp spike in blood pressure. Poorly controlled chronic hypertension is another significant contributor.
Certain underlying medical conditions can also be the source. Kidney disease is a cause, as the kidneys play a large role in regulating blood pressure. The use of certain substances can also provoke a crisis, including illegal drugs like cocaine and amphetamines. Additionally, interactions between different prescription medications can lead to dangerously high blood pressure levels.