People who have a post nasal drip cough should realize their condition is now being called upper airway cough syndrome (UACS). This is a situation where a person has a cough for a long period of time with nasal congestion. It is often caused by mucus dripping down the back of their throat. This causes a person to have a regular sensation they must clear their throat. UACS can cause a person to have a hoarse voice as well as wake up in the morning with something noticeable in the back of their throat. UACS can result from a person having an allergic or a nonallergic reaction to something in their environment. It could also be the result of sinusitis.
The traditional standard study has been a four-view sinus series that includes: (1) the Waters view, in which the occiput is tipped down (patient's chin and tip of the nose are against the film surface) to facilitate viewing of the maxillary and frontal sinuses; (2) the Caldwell view, in which the forehead and tip of the nose are placed in contact with the film (this offers superior visualization of the frontal and ethmoid sinuses); (3) the lateral view, in which the sphenoid sinus and the posterior frontal sinus wall are visualized; and (4) the submentovertex view, in which the sphenoid sinuses and posterior ethmoid cells are visualized.
Saline solutions used in nasal irrigation reduce inflammation through osmosis. Swelling is a major factor in sinus dysfunction. Removal of mucus plays an important role in sinus health, and nasal irrigation facilitates this by flushing out thickened mucus that cannot be handled by the cilia .   improving mucociliary clearance and also removing infected material.  Damage to the mucociliary transport system is an important factor in the development of sinonasal diseases, leading to a stasis of mucus.  The numerous proteins found in nasal mucus include inflammatory mediators , defensins and many whose function is not understood.