Sleeping in the middle of the night and finding fluid coming out of the lower body may be caused by prostatitis, urethritis, premature rupture of membranes, menstrual flow and other factors. 1. Prostatitis: If a man’s prostate gland is infected due to pathogens, or inflammatory lesions caused by irregular sex life, sedentary lifestyle, alcoholism and other factors. It may lead to the appearance of urinary dribbling and purulent urethral secretion, thus the purulent secretion of the urethra will flow out involuntarily when sleeping at night. 2. Urethritis: Inflammatory lesions caused by infection of the urethra by Trichomonas vaginalis, adenovirus, chlamydia, mycoplasma, etc. Itchy urethra, redness and swelling of the urethral orifice, purulent urethral discharge and other symptoms, and the woman may also have leukorrhea and other discomforts. 3. Premature rupture of membranes: It is the spontaneous rupture of membranes before labor, also known as natural rupture of membranes before labor. After the rupture, there will be more fluid coming out from the vagina, and this fluid is colorless and clear in nature. 4. Menstruation: If you are having your menstruation during these days, you may experience menstruation while you are sleeping, and you may feel that there is liquid coming out. This may be accompanied by pain in the lower back, breast tenderness and other discomforts. When the above symptoms appear, it is recommended to consult a doctor in time, under the guidance of the doctor to determine the cause of the disease and then treat it, so as to avoid delaying the best period of treatment.