Hi & Welcome. I can understand your concern. Incomplete data like age, gender, duration of having this problem, any associated medical issues or symptoms, drugs taken??? Frequent urination at night (nocturnal polyuria) can be caused by a number of medical conditions like urinary tract infection, infection or enlargement of the prostate, bladder prolapse, overactive urinary bladder, tumors of the bladder, prostate, or pelvic area, diabetes, anxiety, kidney infection and neurological disorders, such as multiple sclerosis, Parkinson’s disease, or spinal cord compression. You need to consult a urologist for proper evaluation and to rule out the possible causes as of nocturia and to identify the exact cause so that specific treatment may be undertaken. Desmopressin is in a class of medications called hormones. It works by replacing vasopressin, a hormone that is normally produced in the body to help balance the amount of water and salt. It is basically used to control the symptoms of a certain type of diabetes insipidus ( water diabetes ; condition in which the body produces an abnormally large amount of urine). It is also used to control bed-wetting for that it is usually taken once a day at bedtime. Its most common side effects include headache, nausea, upset stomach, or flushing of the face may occur. It can also cause a low level of sodium in the blood, which can be serious and possibly life-threatening. Drinking too much water or other fluids increases the risk of having a low level of sodium in the blood. Hope these answer your queries. Wishing you best of your health.