Signs and symptoms. Only more severe cases of a deviated septum will cause symptoms of difficulty breathing and require treatment. Symptoms of a deviated septum include infections of the sinus and sleep apnea, snoring, repetitive sneezing, facial pain, nosebleeds, difficulty with breathing and mild to severe loss of the ability to smell. The nasal septum is the bone and cartilage in the nose that separates the nasal cavity into the two nostrils.