The nasal septum is a part of the nasal cavity, the inner wall of the nasal cavity, in the middle of the nasal cavity, dividing the nasal cavity into two parts, the front through the nasal aperture to the outside world, and the back through the posterior nasal aperture to the pharyngeal cavity, each side of the nasal cavity can be divided into the nasal vestibule and the intrinsic nasal cavity. It is composed of nasal septal cartilage, septal plate, nasal bone and maxillary frontal process, and the surface is covered with mucous membrane. In normal people, the septum is seldom completely centered, and most of them have some deviation, with a ridge or spine deviation to one or both sides, or an irregular projection into the nasal cavity. There is a venous plexus under the anterior part of the nasal septum, which is a good site for nasal bleeding.