A method of stimulating nasal tissues using a system comprises a catheter assembly connected to a fluid flow generator. The catheter assembly comprises a generally oblong inflatable catheter defining at least one catheter volume and a tube part comprising at least one lumen configured to establish fluid flow connection between said fluid flow generator and catheter. Preferably, the catheter assembly comprises at least one vent for releasing fluid or permitting fluid to escape from the generated fluid flow. The method generally comprises the steps of: providing a fluid flow from the fluid flow generator; inflating the catheter to assume a shape suitable for insertion in the nasal cavity; inserting the catheter to a predetermined position in a nasal cavity; adjusting the catheter with the fluid flow regulator to assume a shape suitable for stimulating the nasal tissue; and stimulating the nasal tissue by selecting at least one of a smooth continuous fluid flow, an oscillating fluid flow and a pulsating fluid flow.