Which shock is caused by massive dilation of blood vessels?

Distributive shock is characterized by massive dilation of blood vessels, which leads to a significant drop in blood pressure and inadequate blood flow to the body's organs and tissues. This dilation can occur due to various reasons, including anaphylaxis, sepsis, or severe neurological injury, all of which disrupt the normal vascular tone. In this state, the blood vessels are unable to maintain adequate blood pressure, even if the blood volume is normal. Consequently, the heart may struggle to circulate blood effectively against this low resistance, leading to cellular hypoperfusion and dysfunction.

Understanding the nature of distributive shock highlights the importance of recognizing the underlying causes of vessel dilation and the body's response. In contrast, hypovolemic shock typically results from a loss of blood volume, cardiogenic shock stems from heart failure where the heart cannot pump effectively, and obstructive shock occurs due to physical obstruction to blood flow, such as in cases of tension pneumothorax or cardiac tamponade. Each of these conditions involves different physiological mechanisms that do not primarily revolve around the massive dilation of blood vessels like in distributive shock.