Deviated nasal septum (DNS) is a condition where the nasal septum, the partition between the two nasal cavities, is misaligned from the midline. This deviation can significantly impact airflow, leading to various respiratory disorders such as nasal obstruction, sinusitis, and impaired breathing. DNS is diagnosed through clinical examination, including anterior rhinoscopy, nasal endoscopy, and imaging methods such as computed tomography (CT), magnetic resonance imaging, and cone-beam CT. These diagnostic tools help to assess the severity of the deviation and its impact on the nasal structures. The classification of DNS is crucial for defining the appropriate treatment plan. Various classification systems have categorized DNS depending on the type, location, and extent of the deviation. Treatment choices of DNS range from conservative nonsurgical remedies such as nasal decongestants and corticosteroids to surgical interventions like septoplasty, which aims to realign the septum and restore normal nasal airflow. This article reviews the prevalence of DNS, different classifications, and various diagnostic approaches for accurate determination and symptoms of DNS. The article also explores the most effective treatment strategies, highlighting the importance of accurate diagnosis and personalized treatment approaches to improve patient outcomes.