With the allergy sufferer, after sneezing and exhaustion, without rest, the sinus infection may become chronic. Weather can make a sinus condition worse, but it is not be a cause. In menstruation and pregnancy there may be swelling of the membranes, but this is not the cause of the sinusitis. Most sinus problems show slow nasal cilia. These are the microscopic hairs that beat to move the bacteria out of the nose into the throat where they are swallowed and the stomach takes them out.
Thick mucus is removed so that the cilia return to normal rate of beating.
If the pressure is too high you can put pus into the ear or other parts of the sinuses. There is a chemical called ICAM - 1 that is the entry way for the common cold virus. Pulsatile irrigation is ideal for removal of this so that the cold virus can't enter. This is also removed by pulsatile irrigation. The flow of the saline past the sinus openings displaces out the pus in the sinus.