What are the long term effects of post nasal drip on asthma?

Poor asthma control: One reason for patients with asthma to fail to gain control of their asthma is "co=morbid" condition including allergies or sinusitis (both common reasons for chronic post nasal drip). When the cause of the post nasal drip is found and treated, the asthma should be easier to control.

Post Nasal Drip: Post nasal drip makes asthma worse typically as the mucous acts as an irritant to the airway. Airway irritation leads to spasm of the air passages which is essentially what happens when you have an asthma attack.