The cause of erectile dysfunction is always due to physical malfunctioning of the penis.
Psychological factors are responsible for causing erectile dysfunction in about 10%-20% of people with the condition. However, the majority of men with erectile dysfunction have an underlying physical condition such as diabetes, heart disease, high blood pressure, have undergone prostate cancer surgery, chronic drug use, or alcoholism.
Erectile dysfunction is just a normal part of growing older and men have to learn to live with it.
It is not normal for a man to lose erectile function completely as a result of aging. Other factors such as vascular disease, diabetes, hypertension, low hormone levels (testosterone), and personal habits may be causing the dysfunction.