Common causes of erectile dysfunction and premature ejaculation are as follows: First, excessive mental stress, tension, and anxiety in men can lead to erectile dysfunction and premature ejaculation. Second, poor lifestyle habits such as staying up late, chronic smoking, and excessive alcohol consumption can also lead to erectile dysfunction and premature ejaculation. Third, as men age, they might experience erectile dysfunction and premature ejaculation, which are normal physiological changes. Fourth, men with certain chronic diseases such as cardiovascular disease, hypertension, diabetes, liver and kidney diseases, especially chronic prostatitis, may experience erectile dysfunction and premature ejaculation.