Functional enuresis is a condition in which children without organic disease still experience frequent unconscious urination and wetting of bedding during sleep after the age of 3 years (especially after the age of 4 to 5 years). It is also defined as persistent bedwetting in children over the age of five, or bedwetting that occurs again when they have been able to control nocturnal urination. Enuresis is confusing and reflects both developmental immaturity and psychological stress to the child. The disease has a genetic predisposition, and children with the disease have a delayed development of the cerebral cortex or sleep too deeply to inhibit the spinal micturition center, and uninhibited contractions of the detrusor muscle occur after sleep to expel the urine. The prognosis is good and most of them heal spontaneously, but physical examination and urinalysis are needed to exclude urinary tract infections and organic diseases (e.g., occult spina bifida), and attention should also be paid to the prevention of psychological disorders. Treatment for enuresis includes wake-up call therapy (gradual formation of biological clock pattern), alarm therapy, medication, biofeedback therapy, etc. In enuresis with combined organic pathology, a urinary system examination and residual urine measurement is advisable to rule out neurogenic bladder. Magnetic resonance examination is done to clarify the presence of spinal cord tethering syndrome, etc.