Sometimes patients, after being diagnosed and given only one to three months to live, may continue living healthy life three months later with the help of performing virtuous deeds such as liberating animals or undertaking a long life practice. When the patients go for check-up again, doctors find the symptoms all gone.. This has happened in Tibet, China and other parts of the world. It is not hearsay or a fairytale but a fact, which somewhat validates the existence of causality. 

~Depicted from FROM BELIEVERS TO BODHISATTVAS