Table 1.

Centers for Disease Control and Prevention classification criteria^a for blast-injured military service members, according to mechanism of injury and result

Classification	Mechanism of Injury	Result
Primary	Overpressurization of internal organs	Lung, ear, and gastrointestinal injuries
Secondary	Objects propelled via shockwave	Fragmentation and penetrating injuries
Tertiary	Victim thrown by air displacement	Fractures and coup-contrecoup injuries
Quaternary	Miscellaneous	Psychiatric and other injuries

^aSource: Centers for Disease Control and Prevention.¹²