The main reason for a four-year-old girl to suddenly urinate frequently, only a little bit each time, is related to factors such as urinary tract inflammation, spinal embolism and other congenital malformations. 1. Inflammation of the urinary tract: If the urine is small, it will cause the increase and reproduction of bacteria, which will lead to urinary tract infection and frequent urination. 2. Congenital malformations such as spinal cord embolism: Congenital malformations such as spinal cord embolism can present with bladder and rectal dysfunction. The former includes enuresis, urinary frequency, urinary urgency, urinary incontinence and urinary retention, while the latter includes constipation or fecal incontinence. Urinary loss or incontinence is most common in children. In addition, in ordinary life, we should pay attention to give children more water, do not eat too many snacks, sweets, eat more fresh vegetables and fruits, pay attention to keep warm. Four-year-old girl suddenly frequent urination each time only a little bit of urine may have other reasons, the patient needs to be timely medical examination, early treatment.