What is a possible physiological sign when a patient has lost 20% of their blood volume?

When a patient has lost approximately 20% of their blood volume, tachycardia, or an increased heart rate, is often observed as a compensatory mechanism. The body recognizes the loss of blood volume, leading to reduced cardiac output and decreased perfusion to vital organs. In response, the heart works harder and beats faster to maintain blood pressure and ensure that oxygenated blood continues to circulate throughout the body.

This physiological response helps to preserve organ function and can be crucial in preventing shock. It indicates that the body is trying to compensate for decreased blood volume in an effort to maintain homeostasis. While tachycardia is commonly seen with such significant blood loss, other signs, such as hypotension, may develop later if blood loss continues and compensatory mechanisms fail.