Background: Unexpected panic attacks may represent a non-specific risk factor for future depression and anxiety disorders. The examination of panic symptoms and associated latent severity levels may lead to improvements in the identification, prevention, and treatment of panic attacks and subsequent psychopathology for ‘at risk’ individuals in the general population. Methods: The current study utilised Item Response Theory to assess the DSM-IV symptoms of panic in relation to the latent severity level of the panic attack construct in a sample of 5,913 respondents from the National Epidemiologic Survey on Alcohol and Related conditions. Additionally, differential item functioning (DIF) was assessed to determine if each symptom of panic targets the same level of latent severity between different sociodemographic groups (male/female, young/old). Results: Symptoms indexing ‘choking’, ‘fear of dying’, and ‘tingling/numbness’ are some of the more severe symptoms of panic whilst ‘heart racing’, ‘short of breath’, ‘tremble/shake’, ‘dizzy/faint’, and ‘perspire’ are some of the least severe symptoms. Significant levels of DIF were detected in the ‘perspire’ symptom between males and females and the ‘fear of dying’ symptom between young and old respondents. Limitations: The current study was limited to examining cross-sectional data from respondents who had experienced at least one panic attack across their lifetime. Conclusions: The findings of the current study provide additional information regarding panic symptoms in the general population that may enable researchers and clinicians to further refine the detection of ‘at-risk’ individuals who experience threshold and sub-threshold levels of panic.