These fact sheets were developed by the National Center for Injury Prevention and Control at the Centers for Disease Control and Prevention. The fact sheets are intended for use by health care providers responding to a mass casualty event that has resulted in blast injuries. The sheets provide information on the essential facts regarding blast injuries, describing key concepts regarding the injured and first responders as well as describing the four types of blast injuries: primary, secondary, tertiary, and quaternary. Primary injuries are those that result from the over-pressurization force impacting the body. Secondary injuries result from projectiles, while tertiary injuries result from displacement of the victim by the blast wind. Quaternary injuries are all other injuries resulting from the blast. The fact sheets present specific information on the following topics: abdominal blast injuries, crush injury and crush syndrome, ear blast injuries, blast extremity injuries, eye blast injuries, blast lung injuries, bombings and mental health, treatment of older adults, pediatrics, post exposure prophylaxis for blood-borne pathogens, pre-hospital care, radiological dispersal devices and radiation injuries, radiological diagnosis, and thermal injuries. Each section contains a brief description of the situation, clinical presentation of the injuries, initial management, disposition and other considerations.