Definition

Orthostatic hypotension is a condition of abnormal blood pressure regulation upon standing. The blood pressure quickly decreases, more than 20/10 mm Hg, when rising from a lying down or sitting position to a standing position.

Measuring of Blood Pressure

Placement of Blood Pressure Cuff

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Causes

As you stand, blood falls toward your lower body in response to gravity. To help keep blood in the upper body:

    
  • Blood vessels in the lower body will tighten to help push blood back up.
  • The muscles in the lower body contract, or squeeze, to help push blood to upper body.
  • The heart will contract a little harder to pump blood up toward the brain.
  • Blood pressure is also affected by the amount of blood in the blood vessels. Low levels of blood will decrease the blood pressure and make it harder for the body to compensate when you stand. Low blood volume called, hypovolemia, is the most common cause of orthostatic hypotension. It may be due to:

        
  • Excessive use of loop diuretic medications
  • Vasodilator medications, such as nitrate preparations, calcium channel blockers, or ACE inhibitors
  • Dehydration
  • Prolonged bedrest
  • Addison’s disease with inadequate salt intake
  • Orthostatic hypotension will occur when one or more of these factors does not work as expected. It may be associated with:

        
  • Diseases or conditions that impair nervous system or nerves that controls the widening or shrinking of blood vessels
  • Decreased ability of the heart to contract or reaction of blood vessels
  • Medications that can affect nervous system or cardiovascular system
  • Alcohol—can slow the reaction of the nervous system
  • Risk Factors

    Factors that increase your chance of orthostatic hypotension include:

        
  • Increased age
  • Use of certain drugs such as:     
  • Loop diuretics
  • Vasodilators
  • MAO inhibitors
  • Tricyclic antidepressants
  • Tetracyclic antidepressants
  • Phenothiazine antipsychotic drugs
  • Quinidine
  • Levodopa
  • Barbiturates
  • Alcohol
  • Inadequate fluid intake
  • Prolonged bedrest
  • Certain diseases or conditions:     
  • Atherosclerosis
  • Advanced heart failure
  • Addison’s disease
  • Diabetes
  • Pernicious anemia
  • Amyloidosis
  • Guillain-Barre syndrome
  • Riley-Day syndrome
  • Multiple system atrophy
  • Symptoms

    Orthostatic hypotension may cause:

        
  • Mild to moderate reduction in brain blood flow:     
  • Faintness
  • Lightheadedness
  • Weakness
  • Confusion
  • Visual blurring
  • Severe reduction in brain blood flow:     
  • Fainting (syncope) or brief loss of consciousness
  • Exercise or having eaten a heavy meal may worsen symptoms.

    Diagnosis

    Orthostatic hypotension is diagnosed when symptoms are present and there is a measured reduction in blood pressure while standing, which is relieved by lying down.

    Treatment

    When possible treatment will focus on resolving the orthostatic hypotension completely. If a complete resolution is not possible, treatment will focus on managing symptoms.

    Resolving Symptoms

    Treatment will depend on the cause. Examples include:

        
  • Adjusting or stopping medications that cause problems.
  • Avoiding prolonged bed rest. Make sure to sit up each day. Start slowly and increase the time and frequency.
  • Preventing dehydration by increasing fluid and electrolyte intake.
  • Managing Symptoms

    Common approaches include:

    The doctor may recommend prescription medications to increase blood pressure.

    Dietary changes may also help increase blood pressure or prevent very low blood pressure. A dietitian may help create a diet plan. Steps may include:

        
  • Increasing salt intake.
  • Eating smaller, more frequent meals with fewer carbohydrates. May help to avoid low blood pressure after eating.
  • Limiting or eliminating alcohol.
  • Behavioral changes that may help include:

        
  • Using fitted elastic stockings that go up to the waist.
  • Learning to slowly move from a lying or sitting position to a sitting or standing position.
  • Avoiding sitting or standing still for prolonged periods of time.
  • Prevention

    There is no way to prevent orthostatic hypotension if it is a result of other diseases or conditions. However, if your orthostatic hypotension relates to medications, dehydration, or bedrest, you should talk with your healthcare provider about treatment options.