Supine hypertension is when a person has high blood pressure when lying down, typically during sleep or rest. Causes may include health conditions, like sleep apnea, and taking certain medications.

A person’s blood pressure typically decreases when they lie down. However, in someone with supine hypertension, blood pressure remains high even when they are in a supine position.

Treatments may include lifestyle changes and medication.

This article discusses what to know about supine hypertension.

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Supine hypertension is a type of hypertension (high blood pressure) that occurs specifically when a person is lying down.

In supine hypertension, a person’s blood pressure is consistently elevated when they are lying down but returns to normal when they are standing or sitting.

Supine hypertension vs. hypertension

“Hypertension” refers to consistently elevated blood pressure, regardless of body position or activity level.

While hypertension and supine hypertension can have similar causes, the diagnostic criteria and treatment approaches differ.

Healthcare professionals typically diagnose hypertension when a person’s blood pressure consistently measures 130/80 millimeters of mercury (mm Hg) or higher.

Healthcare professionals measure blood pressure using systolic pressure and diastolic pressure.

Systolic pressure represents the pressure in the arteries when the heart is contracting. Diastolic pressure represents the pressure in the arteries when the heart rests between beats.

The table below provides a general guideline for blood pressure levels and what they mean:

Systolic pressure (mm Hg)and/orDiastolic pressure (mm Hg)
Normallower than 120andlower than 80
Elevated120–129andlower than 80
Stage 1 hypertension130–139or80–89
Stage 2 hypertension140 or higheror90 or higher
Hypertensive crisishigher than 180and/orhigher than 120

Diagnosing supine hypertension can be challenging because blood pressure measurements in the doctor’s office may not accurately reflect a person’s blood pressure when they are lying down.

Healthcare professionals may use the following diagnostic tests to evaluate supine hypertension:

  • Ambulatory blood pressure monitoring (ABPM): For this test, a person wears a portable blood pressure monitor that takes frequent measurements over 24 hours, including during sleep. This can provide a more accurate picture of a person’s blood pressure levels day and night.
  • Tilt-table test: This test involves lying on a special table that healthcare professionals can tilt to different angles while they monitor a person’s blood pressure and heart rate. This test can help identify autonomic nervous system dysfunction, which can contribute to supine hypertension.
  • Orthostatic blood pressure readings: A healthcare professional takes a person’s blood pressure when they are lying down, seated, and standing.

Blood tests or imaging tests can rule out other underlying causes of symptoms.

Supine hypertension often does not cause any noticeable signs or symptoms.

Some people with supine hypertension may experience symptoms such as:

Common causes and risk factors for supine hypertension include:

  • Autonomic nervous system dysfunction: The autonomic nervous system regulates blood pressure, heart rate, and other involuntary bodily functions. Dysfunction of this system, such as in Parkinson’s disease, multiple system atrophy, or pure autonomic failure, can lead to supine hypertension.
  • Sleep apnea: This condition involves brief interruptions in a person’s breathing during sleep. This can cause fluctuations in blood pressure, including nocturnal hypertension.
  • Medications: Certain medications, such as beta-blockers and some antidepressants, can interfere with blood pressure regulation and contribute to supine hypertension.

Experts frequently associate supine hypertension with orthostatic hypotension, in which the blood pressure drops upon standing.

Studies suggest that about 50% of people who experience neurogenic orthostatic hypotension, a type of orthostatic hypotension resulting from a neurological condition, also develop supine hypertension.

The possible complications of supine hypertension include:

The goal of treatment is to lower nocturnal blood pressure without excessively lowering daytime blood pressure, which can lead to dizziness and falls.

Treatment may involve:

  • Lifestyle modifications: Lifestyle changes, such as reducing salt intake, making efforts to lose weight, increasing physical activity, and avoiding alcohol and tobacco, can help improve blood pressure regulation in people with supine hypertension.
  • Medication adjustments: Changing the timing and dosage of medications can help prevent nocturnal hypertension.

If someone has received a diagnosis of supine hypertension, their doctor may recommend:

  • A different sleep position: Elevating the head of the bed 30 degrees (6–9 inches) can help reduce supine hypertension by improving blood flow to the heart and reducing fluid buildup in the lungs.
  • Monitoring: Regular blood pressure monitoring, including during sleep, can help track the effectiveness of treatment and identify any potential complications.

People can take some steps to reduce the risk of developing supine hypertension:

  • Maintaining a moderate weight: Excess body weight can increase the risk of hypertension, including supine hypertension. Maintaining a healthy weight through regular exercise and a balanced diet can help improve blood pressure regulation.
  • Reducing salt intake: Consuming too much salt can contribute to hypertension, and reducing salt intake can help improve blood pressure regulation.
  • Limiting alcohol and tobacco use: Alcohol and tobacco use can contribute to hypertension and other cardiovascular conditions. Limiting or avoiding these substances can help reduce the risk of supine hypertension.

Supine hypertension, or nocturnal hypertension, is high blood pressure that occurs when a person is lying down, typically during sleep or rest.

The possible causes include autonomic nervous system dysfunction, chronic kidney disease, obesity, sleep apnea, certain medications, and aging.

Supine hypertension may not cause noticeable symptoms but can lead to complications such as heart disease, stroke, and kidney damage unless a person receives treatment.