The reason for 31 years old half month without morning erection may be have normal sex life at night, mental factors and reproductive system diseases. 1. Normal sex at night: If a 31-year-old man is married and has a normal sex life, the number of morning erections will decrease. Especially if you have had sex at night for half a month in a row, androgen levels have peaked at night, and you usually don’t get a morning erection the next morning. 2. Mental factors: If a 31-year-old man is not in a good mood in the last half a month, such as too much tension, depression or anxiety, so that the cerebral cortex activity is reduced, resulting in the control of erection of the central nervous system is inhibited, there may be 31-year-old half a month no morning erection phenomenon. 3. Reproductive system diseases: such as prostatitis, orchitis, penile squamous cell carcinoma and other reproductive system diseases, can lead to insufficient blood congestion of the corpus cavernosum, resulting in erectile dysfunction, thus causing 31 years old and a half months without morning erection. If you are 31 years old and have no morning erection for half a month, you should go to the hospital in time for examination and receive treatment after clarifying the cause of the disease, so as not to cause adverse consequences.