1, sleep-wake dysfunction: refers to the state of sleep, the bladder filling the nerve impulses generated by the child can not be awakened, the child in the non-wakeful sleep state urination, the most important pathogenesis for nocturnal enuresis, there are mainly the following two possible factors: ① bladder filling the nerve impulses generated by the bladder is insufficient to induce awakening; ② sleep is too deep, failed to awakening. 2, nocturnal polyuria: some of the children with enuresis. The kidneys produce a large amount of urine at night, exceeding the maximum bladder capacity. It may be related to the insufficient secretion of antidiuretic hormone by the pituitary gland at night. 3, abnormal bladder function: mainly at night, the bladder capacity caused by over-excitation of the forced urinary muscle is reduced, resulting in more frequent urination, while the amount of urine each time is small. 4, family inheritance: about 62% of children with enuresis parents or other relatives have had a similar history, indicating that the disease may have a genetic predisposition. 5, other: diabetes mellitus, depression and sleep apnea may also be associated with enuresis. Diagnosis and evaluation Children with monosymptomatic nocturnal enuresis have no symptoms other than enuresis, so history taking is extremely important in diagnosis, and physical examination and laboratory tests are feasible when necessary. (I) History inquiry 1. Find out the general condition of the child, including health, development and whether there is any comorbidity of mental illness. 2. 2, the severity of nighttime bedwetting, including the time and frequency of occurrence. Whether there are other symptoms in combination, including daytime urinary frequency, urgency, difficulty in urination or incontinence. Whether it is combined with nocturnal polyuria, and what is the amount of water consumption and drinking habit during weekdays. 5, whether combined with intestinal symptoms, such as constipation or fecal incontinence. 6. Whether urinary loss affects the child’s psychology and daily behavior, and whether it affects social life, study and family relationship. 7. How does the child sleep at night, and whether there is serious snoring or apnea during sleep. 8. Ask the parents about the current measures to deal with nocturnal enuresis, including the method of waking up the child at night to urinate (unawakened, timed or random). (B) physical examination and other tests 1, recommended tests: ① genitourinary system examination; ② routine urinalysis, urinary ultrasound and residual urine volume measurement. 2.Optional examination items: If urinary loss is suspected to be combined with other diseases, such as gastrointestinal symptoms, abnormal physical and intellectual development and/or diabetes mellitus, or suspected neurological diseases, etc., the following examinations can be continued to improve: ①special examination, such as neurological examination, rectal fingerprinting; ②other examinations, including routine blood, blood biochemistry, urodynamics, pelvic radiographs, spinal cord MRI examination. (C) Questionnaires 1. Clinical symptom assessment scale. 2. Voiding diary for at least 3 days. VI. Treatment Since children with monosymptomatic nocturnal enuresis usually have no organic pathology, treatment should start with proper education and guidance. This disease can be self-limiting, some children with increasing age symptoms can gradually disappear, therefore, for children before the age of 6 years can not take drugs or other special treatment. (A) Education and guidance (recommended) 1, first of all, we should emphasize that nighttime bedwetting is not the child’s fault, to avoid being blamed for it, and to encourage the child to carry on normal study and life. 2.Protect the normal daily fluid intake of children with diabetes (Table 2), do not need to restrict their water intake during the day, and reduce the amount of fluids 3 to 4 hours before bedtime. 3.Educate and supervise children to develop good urination habits (4-7 times/day), and try to avoid unnecessary reminders for children’s urination. 4. Parents are advised to use a calendar to keep a detailed record of the presence or absence of enuresis and the number of times it occurs each night, so that the doctor can assess the condition and judge the efficacy of the treatment. (B) The correct method of waking up at night 1, the timing of waking up: do not randomly wake up the child to urinate, should be in the bladder full to the imminent urination to wake them up. Through this method to strengthen the “night urination – wake up” nerve reflex, shorten the duration of urine loss. The following methods can be used to determine that the bladder is full enough to wake up the child to urinate: ① the child suddenly rolls over or shows other signs of restlessness during quiet sleep; ② according to the time pattern of previous urinary loss, wake up the child to urinate before it is about to urinate. In order to make the time of urinary loss more regular and convenient for parents to grasp the wake-up time, the child can be asked to implement the principle of “three fixed” in life: regular dinner, regular sleep, dinner to bedtime drinking water ration. Under the principle of “three fixed”, the amount of urine produced at the corresponding time of the night is relatively stable, and the time of urinary loss will also be relatively fixed. 2, awake state urination: the child will be completely woken up from sleep to awake state urination. (C) urine loss alarm urine loss alarm is a device that can be placed in the bed or the child’s underwear, when the urine loss occurs can issue a warning (sound or vibration, etc.) to wake up the child to urinate. (d) Desmopressin acetate Desmopressin acetate is an antidiuretic hormone analog, is currently the first-line treatment of enuresis. Indications: especially for children with nocturnal polyuria enuresis. Dosage: Currently, desmopressin acetate is commonly used in China as an oral tablet, administered 1 hour before bedtime, with a common dose of 0,2 to 0,4mg (regardless of age and gender). After treatment with desmopressin acetate, some children can have short-term symptomatic improvement, but the symptoms tend to recur after discontinuation of the drug, so it is generally necessary to use continuous medication for at least 3 months. Precautions: Desmopressin acetate has fewer adverse effects and is safer for long-term use, but may cause water intoxication, hyponatremia and convulsions when taken with large amounts of water. Therefore, in order to ensure the safety of medication, it is recommended that parents control the fluid intake of children after dinner to bedtime to less than 200ml until the early morning of the second day. (E) anticholinergic drugs Indications: When the urine loss alarm or desmopressin acetate treatment is not effective, consider using anticholinergic drugs, especially for the combination of nocturnal forced urinary muscle overactivity of the single symptom of enuresis in children can often be achieved satisfactory results. Dosage: Solifenacin or Tolterodine (please refer to the dosage for children) should be taken orally at bedtime. Precautions: The main adverse effects of this drug are dry mouth, constipation and difficulty in urination, etc. Therefore, children must be instructed to maintain good urination habits during the use of the drug, and parents should also pay attention to observing the child’s urination and defecation, and whether it is accompanied by fever, in order to adjust the treatment plan in a timely manner. (F) Tricyclic antidepressants Indications: Tricyclic antidepressants have been commonly used in the treatment of enuresis, but because of their adverse effects, they are only considered for use when the child’s family can not afford enuresis alarms and desmopressin acetate, or after the failure of treatment. Dosage: 25～50mg of promethazine orally at bedtime. the dose of the drug can be increased for children over 9 years of age. Precautions: Tricyclic antidepressants have more adverse reactions, mainly dry mouth, constipation, urinary difficulties, nausea, insomnia and mood changes. The most serious adverse reaction is cardiotoxicity, which can cause fainting, palpitations, arrhythmia and even sudden death. Therefore, its dose must be strictly controlled within the safe range. (VII) Biofeedback therapy Indications: Biofeedback therapy can be considered when educational guidance and medication are not effective. For vesicourethral dysfunction, especially for the combination of functional bladder capacity reduction in enuresis children can often get satisfactory results. Cautions: Biofeedback therapy requires specialized equipment and software, as well as good compliance and a certain degree of understanding of the treatment, and is suitable for older children. (Some scholars believe that some herbs and acupuncture can also help relieve enuresis, but the evidence is not yet sufficient.