Whether surgery is needed for a deviated nasal septum and enlarged turbinates should be determined based on the following aspects.

First, it depends on whether there are clinical symptoms, such as nasal congestion, and particularly if it is severe and persistent, and whether symptoms like nosebleeds and headaches are present. Symptoms are a necessity before considering surgery;

Second, some tests can be conducted, such as a sinus CT scan, to assess the extent of turbinate enlargement and the severity of the nasal septum deviation. If the deviation of the nasal septum is severe, then surgery is absolutely necessary;

Third, some tests related to nasal cavity function can be combined to determine the necessity for surgery. The main function of the nasal cavity refers to its ventilation capability, such as the nasopharyngeal reflex and nasal resistance tests.

An overall assessment of the impact of enlarged turbinates and the deviated septum on the nasal cavity can then guide the decision on whether to undergo surgical treatment.