Orthostatic hypertension is a condition characterized by an excessive rise in blood pressure upon standing. It differs from the more commonly known orthostatic hypotension, where blood pressure drops upon standing. This article aims to explore the nature of orthostatic hypertension, how it is identified, and various approaches to managing it.
Understanding Orthostatic Hypertension
Normally, the body’s autonomic nervous system, particularly the baroreflex, adjusts blood pressure to maintain stability during postural changes. However, in individuals with orthostatic hypertension, this regulatory mechanism overshoots, leading to an exaggerated increase in blood pressure. This condition is also sometimes referred to as postural hypertension.
While many individuals with orthostatic hypertension may not experience noticeable symptoms, some report lightheadedness, dizziness, headaches, heart palpitations, nausea, or sweating upon standing. Fainting is a possible symptom. The underlying causes of orthostatic hypertension are not fully understood but can involve a combination of hemodynamic and neurohumoral factors, such as increased vascular resistance or an overshoot in neurohumoral adjustments to standing. Age is a significant risk factor, with higher prevalence observed in older individuals, and it can also be associated with existing hypertension, diabetes, and obesity.
Identifying Orthostatic Hypertension
Diagnosing orthostatic hypertension involves measuring blood pressure in different body positions. A healthcare professional will first take blood pressure readings while the person is lying down (supine) and then again after they have been standing for a few minutes. A sustained increase in systolic blood pressure of at least 20 mmHg when changing from a supine to a standing position is a common diagnostic criterion. This increase should result in a standing systolic blood pressure of 140 mmHg or higher.
While systolic blood pressure is often the primary focus for diagnosis, an increase in diastolic blood pressure can also be observed. However, a clear medical consensus on the definition for orthostatic diastolic hypertension is still developing. Beyond positional blood pressure measurements, doctors may conduct additional tests to rule out other conditions or identify any underlying medical issues contributing to the blood pressure changes.
Lifestyle Management for Orthostatic Hypertension
Managing orthostatic hypertension begins with lifestyle modifications. Staying well-hydrated is important, as dehydration can affect blood volume and pressure regulation. Increasing sodium intake, under medical guidance, can help the body retain fluids and support blood pressure. However, excessive salt intake can pose other health risks, so this should be carefully monitored.
Other lifestyle adjustments include:
- Eating smaller, more frequent meals and limiting rapidly digested carbohydrates and alcohol.
- Engaging in regular, light physical activity, such as swimming or recumbent cycling.
- Avoiding sudden changes in position, prolonged standing, and hot environments like saunas or hot baths.
- Wearing compression stockings to aid blood flow from the legs back to the heart.
- Elevating the head of the bed slightly during sleep.
Pharmacological Interventions
When lifestyle modifications are insufficient to manage orthostatic hypertension, pharmacological interventions may be considered. Medications aim to regulate blood pressure and heart rate by affecting fluid retention, blood vessel constriction, or the nervous system. For instance, fludrocortisone helps increase blood volume by reducing the loss of sodium and water.
Midodrine works as a vasoconstrictor, narrowing blood vessels to raise blood pressure. Droxidopa, a prodrug of noradrenaline, is another option to improve standing blood pressure. These medications must always be prescribed and monitored by a healthcare professional due to potential side effects and interactions. Managing any underlying medical conditions that contribute to orthostatic hypertension is also a significant part of the overall treatment plan.