Patent Foramen Ovale: A Comprehensive Guide
Medically reviewed by Andre Stone | MD, University of Pittsburgh School of Medicine on August 24th, 2026.
Published on April 7th, 2026. Updated on August 28th, 2026.
Key Takeaways
Patent foramen ovale (PFO) is a hole in the heart wall that fails to close after birth, affecting about 25% of the population
Most people with PFO never experience symptoms and live normal, healthy lives
PFO can be associated with certain otherwise unexplained strokes and with decompression illness in divers. Migraine is more common among people with PFO, but it is uncertain whether the PFO causes the headaches, and closure is not routinely recommended solely to treat migraine.
Diagnosis requires specialized heart imaging tests like echocardiography with bubble study
Treatment ranges from monitoring to surgical closure, depending on symptoms and stroke risk
Overview
Patent foramen ovale (PFO) is a heart condition where a small opening between the heart's upper chambers fails to close after birth. During fetal development, this opening allows blood to bypass the lungs. Normally, it seals within the first year of life.
About 25% of adults have a PFO that never closed completely. Most people with PFO live their entire lives without knowing they have it. The condition affects men and women equally across all age groups.
While PFO is often harmless, it can sometimes allow blood clots to travel from the right side of the heart to the left side. This may increase the risk of stroke or other complications. Understanding your risk factors helps doctors determine if treatment is needed.
The opening is typically very small, usually smaller than a grain of rice. This tiny size explains why most people with PFO never have any problems. Your heart still pumps blood normally even with this small hole present.
Symptoms & Signs
Most people with patent foramen ovale experience no symptoms at all. When symptoms do occur, they're often related to complications rather than the PFO itself.
Primary Symptoms
Sudden weakness or numbness on one side of the body (possible stroke symptoms)
Severe headaches that may worsen with physical activity
Shortness of breath during exercise or daily activities
Blue coloring of the lips or fingernails (rare, indicates low oxygen)
When to Seek Care
Call 911 or your local emergency number immediately for sudden weakness, numbness, trouble speaking, severe chest pain, or other possible signs of stroke or a serious complication. Seek immediate care for a severe headache that feels different from your usual headaches.
After treatment, discuss changes in migraine symptoms or exercise tolerance with your doctor so the cause can be evaluated.
When to Seek Immediate Care
Call 911 immediately if you have sudden weakness, trouble speaking, or severe chest pain. These could be signs of stroke or other serious complications.
Causes & Risk Factors
Patent foramen ovale occurs when the natural opening between heart chambers doesn't close properly after birth. This happens during normal fetal development but fails to complete the closing process.
The exact reason why some people's foramen ovale stays open isn't fully understood. It appears to be a random developmental variation rather than something caused by lifestyle or environmental factors.
Before birth, babies don't use their lungs to breathe, so the foramen ovale helps blood skip the lungs. After birth, babies take their first breath and the hole usually closes on its own. Sometimes this closing mechanism doesn't work completely.
Age
PFO is present from birth and doesn't develop later in life
Genetics
Family history may slightly increase likelihood, but no specific genes identified
Lifestyle
No lifestyle factors cause PFO, but some activities may increase complication risk
Other Conditions
Certain blood-clotting disorders can increase the risk of a clot that could travel through a PFO. Your doctor may consider testing when your medical or family history suggests such a disorder.
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Diagnosis
Medical History & Physical Examination
Your doctor will ask about symptoms like headaches, shortness of breath, or any history of stroke. They'll listen to your heart and lungs with a stethoscope. Most people with PFO have normal physical exams, so specialized testing is usually needed.
The doctor may ask about diving activities, recent long flights, or family history of heart problems. They'll also review any previous imaging studies of your heart or brain.
Diagnostic Testing
Echocardiogram with bubble study - Uses ultrasound and saline bubbles to detect blood flow through the PFO
Transesophageal echocardiogram - Provides detailed images by placing the ultrasound probe in the esophagus
Transcranial Doppler - Detects bubbles reaching brain blood vessels, which can show a right-to-left shunt; heart imaging is usually needed to determine whether a PFO is the cause
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Treatment Options
Treatment for patent foramen ovale depends on whether you have symptoms and your risk of complications. Many people need no treatment at all.
Conservative Treatments
Observation and monitoring - Regular check-ups to watch for new symptoms or complications
Blood thinning medications - Aspirin or stronger blood thinners to reduce clotting risk
Migraine prevention medicines - For people whose headache symptoms may be related to PFO
Advanced Treatments
Percutaneous PFO closure - Minimally invasive procedure using a small device to seal the opening
Surgical closure - Open-heart surgery to close the PFO, rarely needed except in complex cases
Your doctor will discuss which treatment option is best based on your age and health history. Some people may be prescribed aspirin or another medication to reduce clotting risk. Take these medicines only as directed by your healthcare professional because they can cause bleeding and are not appropriate for everyone. Others may need stronger medications or even a procedure to close the hole.
The decision to treat PFO depends on whether you've had a stroke or other serious events. People without symptoms often don't need any treatment at all. Your cardiologist will help you understand the pros and cons of each choice.
Living with the Condition
Most people with patent foramen ovale can participate in all normal activities without restrictions. Regular exercise and maintaining good cardiovascular health are important for everyone.
If you take blood-thinning medications, learn to recognize signs of bleeding. Keep a list of your medications and inform all healthcare providers about your PFO diagnosis. Wear medical alert jewelry if you take blood thinners.
Stay up to date with preventive care including vaccinations. Some infections can increase blood clotting risk, so preventing illness when possible is beneficial.
Having PFO means making smart choices about your activities and health. You can still do the things you love like playing sports and traveling. Just follow your doctor's advice about any restrictions or precautions.
Daily Management Strategies
Follow your medication schedule exactly as prescribed. Monitor for unusual bruising or bleeding if taking blood thinners. Keep regular appointments with your cardiologist to monitor your condition. Maintain good dental hygiene to prevent infections that could affect your heart.
Exercise & Movement
Most people with PFO can exercise normally without restrictions. Swimming, walking, and other aerobic activities are generally safe and beneficial. Consult your doctor before starting new intense exercise programs or activities like scuba diving.
Prevention
Patent foramen ovale cannot be prevented since it's a developmental variation present from birth. However, you can reduce the risk of complications through healthy lifestyle choices.
Maintain a healthy weight and exercise regularly to reduce cardiovascular disease risk
Don't smoke, as smoking increases blood clotting and stroke risk significantly
Manage other health conditions like high blood pressure and diabetes effectively
Stay hydrated during air travel and move around frequently on long flights to prevent blood clots
Eating a healthy diet with plenty of fruits and vegetables helps your heart stay strong. Staying adequately hydrated is sensible, especially during travel or illness, but it does not replace proven measures for preventing blood clots or stroke. Getting enough sleep each night is also important for heart health.
Frequently Asked Questions
PFO doesn't typically get larger or worse with age. The opening size usually stays the same throughout life. However, your risk of complications may change based on other health factors.
Most people with PFO can fly safely. Stay hydrated, move around during long flights, and consider compression socks. If you have a history of blood clots, talk to your doctor about additional precautions before travel.
PFO generally doesn't cause problems during pregnancy. However, pregnancy slightly increases blood clotting risk. Discuss your PFO with your obstetrician to ensure proper monitoring during pregnancy and delivery.
Routine screening of family members isn't usually recommended since most PFOs cause no problems. Testing is only considered if someone has unexplained stroke or other concerning symptoms.
PFO alone rarely causes heart failure. Most people with PFO have normal heart function. If you develop symptoms of heart failure, other heart conditions are more likely causes and need proper evaluation.
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