In general, men in their 40s will have morning erections under normal circumstances, but the frequency and duration of morning erections will be lower than when they are younger, which is a normal phenomenon. Morning erection is a normal physiological phenomenon that occurs when a man has an erection in the morning from 4 to 7 a.m. when the penis is unconsciously excited by the parasympathetic nerves, and is not controlled by the situation, action, or thought. After most men reach sexual maturity at around 13 years of age, morning erections become more frequent and last longer as they grow older. after 30 years of age, morning erections will gradually weaken or decline as they grow older. a man in his 40’s should have morning erections, but the frequency and duration of morning erections are less than when he is younger, which is a normal condition. If the patient is 40 years old, morning erection disappears, may need to go to urology or male specialists, mainly to rule out impotence and other sexual dysfunction diseases. 40-year-old men will have morning erections, the frequency and duration of the change, specific can consult the relevant professional doctors, other uncomfortable symptoms in time to consult the doctor.