Understanding the causes of erectile dysfunction is a prerequisite to comprehending how Fildena 25 functions. PDE is the cause of this growing problem in our bodies. We have read about a few circumstances in the opening paragraph that explain why this problem occurs. PDE manifests in the body when an individual fails to provide adequate care for their health. Erection dysfunction begins when the blood vessel's radius that supplies blood to the penis narrows as a result of PDE activation.