Some substances are more toxic than others. The toxicity of a substance is described by the types of effects it causes and its potency. 1  Types of Effects: Different chemicals cause different effects.
I think I remember reading that injured means bruises and lascerations, seriously injured meant hospital but not life threatening, critically injured meant hospital ICU time and fatally injured meant injuries leading to dying sometime later.
In physical medicine, major trauma is injury or damage to a biological organism caused by physical harm from an external source. Major trauma is also injury that can potentially lead to serious long-term outcomes like chronic pain. A traumatic injury is an injury caused by external force, but which does not rise to the level of major trauma. Traumatic injuries are distinguished from other causes of injury, such as iatrogenic injuries.