The phenomenon of erection in men in the morning is mainly due to the fact that they have not had sex recently or they do not have the habit of masturbating, thus the sperm is stored in the seminal vesicles and when it reaches a certain amount, it triggers the urge to ejaculate, thus triggering an erection. There are also cases where men have the habit of drinking a lot of water before going to sleep at night, thus resulting in more urine in the bladder in the morning, which triggers the erectile nerve in the body, generating excitability and leading to the appearance of a morning erection. In this case, the patient will have a feeling of swelling and fullness in the lower abdomen. After going to the bathroom to urinate and emptying the bladder, the morning erection will gradually disappear and the penis will weaken. Men do not have obvious symptoms of discomfort, but if there are frequent morning erections and some symptoms of discomfort, such as loss of energy, lack of strength, soreness and weakness of the waist and knees, or if the penis does not weaken on its own during the morning erection, it is recommended that patients go to the hospital for a timely examination to prevent abnormal penile erections.