A nasal EPAP dilator is employed as an intranasal device which effect differing degrees of inhibition/easing for exhalation/inhalation. A nasal dilator incorporates an outer housing that functions as a pair of connected mirror image nasal dilators, combined with a differential-action valve mechanism modulating the airflow through the passages defined by the dilators, when inserted. The valve greatly inhibits exhalation, while opening easily to inhalation which in combination with the dilating effect is thereby eased over the absence of the nasal dilator. The nasal dilator housings include spars or a screen for structural support and a stoppage mechanism for the valves and to moderate the degree of movement of a plurality of valves so that the valves can open for inhalation, and are restrained to mostly close during exhalation.
