The nasal vein is a vessel that carries blood from the nose to the cranial cavity. It is one of the most important elements of the venous system, as it ensures venous outflow and reduces swelling of the mucous membrane. The nasal vein has several branches that leave the ethmoid bone and go to the inner lining of the dorsum of the nose. The two most important branches, the nasolacrimal and nasolopubic veins, merge into the central nasal vein, which exits through the openings in the lower part of the turbinates and flows into the paranasal sinus. If you have a disease in the nasal cavity or paranasal sinus, there may be problems with blood flow, which can lead to swelling and blurred vision. Treatment of nasal vein diseases can be surgical or conservative.