Foramen ovale does not close - what are the consequences?

Usually nothing. 20-25% of all adults have pfo. Most live thier entire lives without problems related to the pfo. Some people have strokes that are thought to be related to pfo, and it has also been associated with migraine headahces and decompression illness in scuba divers. There is no evidence to indicate that pfo should be treated unless a person has problems thought to be directly related to the pfo.