Normal night erection frequency is about 4-6 times, each erection 20-30 minutes, for normal erection, relax, if far beyond this or accompanied by pain may be abnormal penile erection, should be promptly diagnosed and treated. 1. Normal erection: it is a normal physiological phenomenon in men, healthy men will have a spontaneous erection during sleep, the frequency of normal nighttime erection is about 4-6 times, each erection is 20-30 minutes, a total of up to 2-3 hours or so, it is a normal erection, the patient’s body can be relaxed. 2. Abnormal erection: When the penis continues to be erect for more than one hour or even longer, it is abnormal erection. It can be categorized into arterial abnormal erection and venous abnormal erection. Depending on the condition of the patient, the doctor may give observation, sponge puncture and other treatment options. It should be noted that nocturnal penile erection is a normal physiological phenomenon, if there is no pain do not interfere without authorization, it is best to relax first. In addition, when the erection pain should be timely medical treatment, so as not to delay the condition.