Frequent urination during the day can be caused by inflammation of the urethra, improper dietary habits, mental and psychological factors. 1. Inflammation of the urethra: after the occurrence of inflammation of the urethra in children, frequent urination and other symptoms during the day, usually drink less water at night, resulting in less urethral irritation, there may be no obvious abnormality. 2. Improper dietary habits: children like to eat watermelon and other sugary foods, which can promote diuresis, leading to frequent urination. Wearing too tight underwear during the day can lead to irritation of the urethral or vulvar opening, which can also cause frequent urination. 3. mental psychological factors: children during the day mental emotional tension, the symptoms of frequent urination, night sleep mental state is more relaxed, may not appear frequent urination and other performance. Children daytime urinary frequency should be timely medical treatment, under the guidance of specialists to actively carry out appropriate treatment, will help to alleviate the discomfort symptoms as soon as possible.