###Human: Please advice a permanent solution for post nasal drip. ###Assistant: Hello. Postnasal drip occurs due to rhinosinusitis or nasopharyngitis and is rightly said to be allergic which is exacerbated by infections. Treating the underlying cause helps in mitigating (making less severe) these symptoms. Allergic rhinitis or rhinosinusitis can be difficult to treat. One important part is avoiding the allergens of which particularly important is house dust. Use of antihistamines and nasal spray should be judiciously done as and when required. You may try clearing your nose and sinuses by using a neti pot or nasal douching as required.