UASC may be related to postnasal drip, but some are not obviously related, such as sinusitis, paranasal sinusitis, and chronic pharyngitis. Sinusitis, and chronic pharyngitis can also be classified as one of them. Among them, allergic rhinitis is closely related to the cause of UACS. In clinical practice, if allergic rhinitis is effectively controlled, it is beneficial to control the cough caused by UACS and even reduce asthma attacks. Therefore, we should pay attention to the treatment of allergic rhinitis. Generally the cough of UACS occurs in the morning, or there is a change of position with paroxysmal cough, which may have a large amount of sputum production, but the cough decreases or even disappears during the day, and no significant cough occurs at night. So why should we pay attention to UACS treatment? Because it is one of the causes of chronic cough in children and may even cause asthma, so it is important to pay attention to early treatment and prevention.