Morning erection is very hard at room service is not hard belongs to erectile dysfunction. It may be caused by physiological reasons such as excessive masturbation or pathological reasons. 1. Physiological reasons: frequent masturbation or too frequent sexual intercourse can damage the corpus cavernosum and lead to erectile dysfunction. Excessive fatigue or over-exercise, emotional stress or low mood can also easily trigger erectile dysfunction. 2. Pathological causes: (1) prostatitis: prostatitis caused by prostate tube blockage makes the prostate gland distended, oppression of the sexual nerve around the prostate, the pathogen produces toxins and purulent substances, directly stimulate the nerve tissue of the prostate gland, causing neurasthenia and so on, thus leading to erectile dysfunction. (2) diabetes mellitus: diabetic patients with lesions of the peripheral nerves, can affect the sense of touch of the penis, thus reducing the erectile response of the penis. If the damage occurs to the autonomic nerves on the cavernous body of the penis, it can make the regulation of blood vessels in the erectile tissue go out of control, and the congestion of the cavernous body can not be completed, thus leading to erectile dysfunction. Patients with erectile dysfunction are advised to go to the hospital in time for treatment.