The present invention relates to a tamponade for nasal cavities or sinus cavities, for the uniform force-applying tamponade of a cavity of the nasal tract in the region of an ostium leading to the cavity, comprising a thin-walled balloon made from a soft foil-like, only slightly expandable, smoothly folding polyurethane material, with a wall thickness in the range of 5 to 50 μm, which is already completely shaped with the required tamponade dimensions or greater at the time of production, thus to be expanded without application of filling pressure, which balloon in the filled condition thereof occupies the respective, generally irregular-shaped cavity and the ostium of same, through the development of forces, that are as uniform as possible, on the structures exposed to the balloon, in such a way that a distal segment of the balloon is located inside the cavity to be applied with a tamponade, a proximal segment of the balloon is located in front of the cavity and a transostial segment of the balloon extends
