Patient Secret Keeping

I'm a nurse at a small community hospital, and there's this one patient who came in for some routine check-ups. They confided in me about something very personal and private that has nothing to do with their health, but it's been weighing on my mind ever since. As a nurse, I've always prided myself on maintaining strict confidentiality, yet here I am, unsure if I should share this information or keep it to myself because it could potentially affect them in the future. What would you guys do in my shoes? How do you balance discretion with potential concern for someone's wellbeing?