Rare diseases · Sign or symptom

Patent foramen ovale

HP:0001655

What it means

Failure of the foramen ovale to seal postnatally, leaving a potential conduit between the left and right cardiac atria.

The foramen ovale is located in the atrial septum and is essential for proper fetal circulation. With separation from the placenta and with the first few breaths, the left atrium fills with blood returning from the lungs and closes the foramen ovale. Subsequently, during the first years of life, the foramen ovale seals shut.

Rare diseases that can present with this42

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Persistent foramen ovale · PFO

Patent foramen ovale

Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.

Start free with Eleplan

This page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.