A hypertensive disorder refers to high blood pressure, a common medical condition where the force of blood against artery walls is consistently too high. This sustained pressure can damage arteries over time, potentially leading to serious health complications. It is a widespread condition that often goes unnoticed, earning it the nickname “silent killer”.
Understanding Hypertension: The Basics
Blood pressure is measured as two numbers: systolic and diastolic, expressed in millimeters of mercury (mmHg). The systolic pressure, the top number, indicates the pressure in your arteries when your heart beats and pumps blood. The diastolic pressure, the bottom number, represents the pressure in your arteries when your heart rests between beats.
According to the American College of Cardiology/American Heart Association (ACC/AHA) guidelines, normal blood pressure is less than 120 mmHg systolic and less than 80 mmHg diastolic. Elevated blood pressure, sometimes called pre-hypertension, is defined as a systolic pressure between 120 and 129 mmHg and a diastolic pressure less than 80 mmHg. Stage 1 hypertension is diagnosed when systolic pressure is between 130 and 139 mmHg or diastolic pressure is between 80 and 89 mmHg. Stage 2 hypertension is characterized by a systolic pressure of 140 mmHg or higher, or a diastolic pressure of 90 mmHg or higher.
Types of Hypertensive Disorders
Primary hypertension, also known as essential hypertension, is the most common form, accounting for 90-95% of all cases. For this type, there is no identifiable underlying medical cause; it develops gradually over many years, often influenced by genetic factors, lifestyle choices, and age.
Secondary hypertension is high blood pressure caused by an underlying medical condition or medication. Examples include kidney disease, thyroid problems, adrenal gland tumors, or the use of certain drugs. Addressing the underlying condition can often resolve this type of hypertension.
Hypertensive disorders can also arise during pregnancy. Gestational hypertension develops after 20 weeks of gestation and is characterized by new-onset high blood pressure without other signs like protein in the urine.
Preeclampsia is a more severe pregnancy-related hypertensive disorder, occurring after 20 weeks of gestation. It involves high blood pressure alongside signs of organ dysfunction, which can include:
Proteinuria (protein in the urine)
Low platelet count
Impaired liver function
Kidney insufficiency
Pulmonary edema
New-onset cerebral or visual disturbances
Eclampsia is the most severe form of preeclampsia, characterized by the onset of seizures in a woman with preeclampsia. These seizures can occur before, during, or after delivery.
A hypertensive crisis is a sudden, severe increase in blood pressure, typically with readings of 180/120 mmHg or higher. This condition is categorized into two types: hypertensive urgency and hypertensive emergency. Hypertensive urgency involves very high blood pressure without immediate evidence of organ damage, while a hypertensive emergency includes severe blood pressure elevation accompanied by new or worsening organ damage, affecting areas like the heart, brain, kidneys, or eyes.
Recognizing Hypertensive Disorders: Symptoms and Diagnosis
Hypertension often presents without obvious symptoms, meaning many individuals can have high blood pressure for years without realizing it. Symptoms usually appear only when the condition is severe or has caused organ damage. When symptoms do occur, they are generally non-specific and can include:
Severe headaches
Shortness of breath
Nosebleeds
Blurred vision
Chest pain
Dizziness
Anxiety
These symptoms warrant immediate medical attention, especially if blood pressure readings are significantly elevated.
Diagnosing hypertensive disorders primarily relies on consistent blood pressure measurements. A healthcare provider will measure blood pressure during routine check-ups, using an inflatable cuff around the arm. If initial readings are high, multiple measurements taken on separate occasions, often over several weeks, are used to confirm a diagnosis. Home blood pressure monitoring or ambulatory blood pressure monitoring (ABPM), which records blood pressure over a 24-hour period, may also be recommended to provide a more comprehensive picture of blood pressure patterns outside of a clinical setting.
Potential Health Implications
Untreated or poorly managed hypertensive disorders can lead to health complications, affecting various organ systems. The cardiovascular system is vulnerable, as sustained high blood pressure forces the heart to work harder, which can lead to the thickening and enlargement of the heart muscle, a condition known as left ventricular hypertrophy. This increased strain also contributes to atherosclerosis, a buildup of plaque in the arteries, which narrows vessels and restricts blood flow, increasing the risk of heart attacks and strokes. High blood pressure can also lead to heart failure, where the heart struggles to pump enough blood to the body.
Beyond the heart, kidneys are also susceptible to damage from prolonged high blood pressure. The elevated pressure can harm the arteries surrounding the kidneys, impairing their ability to filter blood properly and potentially leading to chronic kidney disease or even kidney failure. The eyes can also be affected, as high blood pressure can damage the delicate blood vessels in the retina, a condition known as hypertensive retinopathy, which may result in blurred vision or vision loss. Additionally, the brain can suffer from impaired blood flow and oxygen supply due to damaged blood vessels, increasing the risk of transient ischemic attacks (mini-strokes), vascular dementia, and other cognitive impairments.