Dear Patient, Thank you very much for your question. In Mitral valve regurgitation or mitral insufficiency, your mitral valve does not close tightly,therefore,it allows to flow blood backward in your heart. Upon severity of Mital valve regurgitation, patients can be no symptoms in mild cases or experience heart palpitations, shortness of breath,fatigue, swollen feet or ankles upon disease progression. Also physician can hear the presence of murmur during auscultation. In your sister s case, since her mitral valve regurgitation is mild nothing much to worry about it. However, I would recommend her to take an echocardiogram once every year. Maintaining a healthy blood pressure,doing regular exercises, avoiding from smoking and drinking alcohol,maintaining a normal body weight can be helpful to stop progressing this condition. Again, MVP is a very prevalent condition especially among females. Follow those recommendations and consult a cardiologist if she only develops the above mentioned symptoms. Most people have mild regurgitation throughout their entire life without any progression. Therefore, nothing to worry. If you have more questions, please let me know. Good luck! Dr. Dinesh Nuwan Weerasinghe. MD