A loss of which percentage of body weight may be fatal?

• A. 2% of body weight
• B. 5-10% of body weight
• C. 10-15% of body weight
• D. 15% or more of body weight

Answer: (D)

Significant fluid loss translates directly into a dramatic drop in circulating blood volume, which shortens the body's ability to perfuse vital organs. When about 15% or more of body weight is lost, the remaining fluid and electrolytes are usually insufficient to maintain blood pressure and tissue oxygen delivery. This sets up hypovolemic shock and can lead to organ failure and death if not rapidly corrected with fluids and medical support. Lower losses—2% or 5-10%—produce noticeable symptoms like thirst, dizziness, and fatigue but are not typically life-threatening on their own. Even 10-15% is extremely dangerous; the risk of fatal outcomes becomes most imminent around 15% or more, especially if the loss occurs quickly. This threshold helps clinicians assess when urgent intervention is required.