are both the number one and two causes of traumatic death. For statistical purposes, injuries are classified as either intentional such as suicide, or unintentional, such as a motor vehicle collision. Intentional injury is a common cause of traumas. Penetrating trauma is caused when a foreign body such as a bullet or a knife enters the body tissue, creating an open wound. In the United States, most deaths caused by penetrating trauma occur in urban areas and 80% of these deaths are caused by firearms. Blast injury is a complex cause of trauma because it commonly includes both blunt and penetrating trauma, and also may be accompanied by a burn injury. Trauma also may be associated with a particular activity, such as an occupational or sports injury. Pathophysiology The body responds to traumatic injury both systemically and at the injury site. This response attempts to protect vital organs such as the liver, to allow further cell duplication and to heal the damage. The healing time of an injury depends on various factors including sex, age, and the severity of injury. The symptoms of injury may manifest in many different ways, including: Altered mental status Fever Increased heart rate Generalized edema Increased cardiac output Increased rate of metabolism Various organ systems respond to injury to restore homeostasis by maintaining perfusion to the heart and brain. Inflammation after injury occurs to protect against further damage and starts the healing process. Prolonged inflammation may cause multiple organ dysfunction syndrome or systemic inflammatory response syndrome. Immediately after injury, the body increases production of glucose through gluconeogenesis and its consumption of fat via lipolysis. Next, the body tries to replenish its energy stores of glucose and protein via anabolism. In this state the body will temporarily increase its maximum expenditure for the purpose of healing injured cells. Diagnosis The initial assessment is critical in determining the extent of injuries and what will be needed to manage an injury, and for treating immediate life threats. Physical examination Primary physical examination is undertaken to identify any life-threatening problems, after which the secondary examination is carried out. This may occur during transportation or upon arrival at the hospital. The secondary examination consists of a systematic assessment of the abdominal, pelvic, and thoracic areas, a complete inspection of the body surface to find all injuries, and a neurological examination. Injuries that may manifest themselves later may be missed during