Nasal septal hematoma is a collection of blood under the mucoperichondrium or mucoperiosteum of the nasal septum caused by trauma or surgery. Symptoms include nasal obstruction, pain, rhinorrhea, and fever. Examination reveals asymmetry of the septum with bluish or reddish swelling. Treatment involves urgent drainage of the clot under local anesthesia to prevent complications like abscess or deformity. Late drainage can lead to issues like a saddle nose deformity or sinusitis. Proper technique involves incising the mucosa and suctioning out the clot while irrigating with saline.