An abnormally increased amount of time required to clear mucus (and substances contained in the mucus) from the nasal mucosa. The nasal mucociliary clearance (NMC) system functions to transport the mucous layer lining the nasal epithelium towards the naso pharynx by ciliary beating in a metachronous fashion at a frequency of 7-16 Hz. NMC depends upon two principal components [from
HPO]