Mild to moderate simple obesity has little effect on sexual function, while severe obesity has an effect on sexual function. Obesity is a kind of disease that is formed by many factors that lead to excessive accumulation of fat in the human body. Obesity can affect men’s sexual function through the change of sex hormone level, chronic diseases such as three high, psychological factors and so on. 1. There are many factors of sexual dysfunction, such as high blood pressure, diabetes, smoking, etc., and obesity is a risk factor for many diseases, such as hypertension, diabetes, hyperlipidemia, coronary heart disease and stroke. 2. As weight increases, testosterone levels tend to decrease. The aromatase enzyme in the adipose tissue of obese men converts testosterone into estrogen, and the increase of estrogen level and the decrease of testosterone may affect the sexual function. 3. Obesity can cause psychological changes in men, such as anxiety, depression and so on, which can cause the patient’s self-confidence to decline, leading to sexual dysfunction. Therefore, men should develop the habit of exercising in their daily life, so as to prevent the decline of sexual function, and if there is any related discomfort, please seek medical treatment as soon as possible.