Pulsus Paradoxus

Pulsus paradoxus is a larger-than-normal drop in systolic blood pressure when you inhale. This top number is your blood pressure against your artery walls during heartbeats. There are several ways your provider can check for this sign of a heart or lung condition. Pulsus paradoxus has many causes. Treating them makes pulsus paradoxus go away.


What is pulsus paradoxus?

Pulsus paradoxus is a phenomenon when your blood pressure decreases with inhalation (breathing in). It’s a sign that you have a condition that affects your heart or lungs. But only your healthcare provider will notice it.

Pulsus paradoxus can happen when people have certain heart or lung diseases. It’s a paradox because it’s the opposite of what you’d expect to happen in the absence of heart or lung disease. (Blood pressure should increase with inhalation). It happens because of pressure changes in and around your heart. These changes affect the filling of your heart chambers.

Blood in your heart chambers goes to your lungs to pick up oxygen and then to your body to deliver oxygen-rich blood. If a disease or condition limits the amount of blood your heart can handle, that limits the amount of blood your body’s cells can receive.

How to measure pulsus paradoxus

Using a manual blood pressure cuff, your healthcare provider will:

  • Inflate the cuff until they don’t hear pulse sounds with a stethoscope or ultrasound wand. They can also use a pulse oximetry monitor to find pulse sounds.
  • Deflate the cuff slowly (2 millimeters of mercury per second) and listen for a pulse.
  • Check the pressure while you’re exhaling.
  • Deflate the cuff a little more.
  • Check the pressure again while you’re breathing in and out and your provider can hear your pulse.
  • Figure out the difference between the two systolic (top) numbers from when you breathe in and breathe out.

You could have pulsus paradoxus if the difference between the numbers is higher than 10 millimeters of mercury (mmHg).

Note: Providers can use a catheter in your artery to check for pulsus paradoxus. They may use this invasive method in an intensive care setting.


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Possible Causes

What causes pulsus paradoxus?

A large pericardial effusion is the most common cause of pulsus paradoxus. Normally, you have some fluid in your pericardium, or sac around your heart. This gives your heart protection and cushioning. But sometimes, too much fluid builds up in your pericardium. Providers call this pericardial effusion. This fluid buildup presses on your heart because your pericardium can only stretch so much. When the fluid buildup squeezes the heart so much that blood can’t enter, it becomes cardiac tamponade.

Other pulsus paradoxus causes include:

In causes that don’t involve your pericardium, both blood pressure numbers (top and bottom) usually fall.

Care and Treatment

What are the treatments for a condition with pulsus paradoxus?

Pulsus paradoxus isn’t an illness and requires no specific treatment. It’s something your provider can use during a clinical exam to figure out if your underlying lung or heart disease is affecting the function of your heart chambers. Providers use pulsus paradoxus to make decisions about when to intervene on your lung or heart disease.

Conditions that cause pulsus paradoxus make it hard for your heart or lungs to function. Some of these conditions put pressure on your lungs or heart. Others involve narrow or blocked parts in your lungs or heart.

Treatment involves relieving pressure on your organs or opening up narrow airways or heart valves, for example.

Treatments to resolve these issues in your heart or lungs may include:

  • Pericardiocentesis or surgery for cardiac tamponade.
  • Surgery or medication for constrictive pericarditis.
  • Medicine, surgery or a minimally invasive procedure for a heart attack.
  • Medicine, drainage of the fluid, scar tissue creation or surgery for pleural effusion.
  • Medicines for restrictive cardiomyopathy.
  • Medicines for asthma.
  • Medicine and surgery for tricuspid atresia.
  • Medicine or surgery for a pulmonary embolism.
  • Air drainage or surgery for a collapsed lung.
  • Medication, physical therapy or surgery for thoracic outlet syndrome.
  • Medicines and extra oxygen for COPD.
  • Surgery to correct pectus excavatum.

A note from Cleveland Clinic

Pulsus paradoxus tells your healthcare provider — or confirms — that you have an issue with your heart or lungs. They’ll treat the source of the issue so your heart and lungs can work better. Treatment can involve medications, procedures or surgery. Be sure to follow your provider’s instructions and go to all follow-up appointments.

Medically Reviewed

Last reviewed on 12/29/2022.

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