In a supine patient, the absence of visible jugular venous distention is most consistent with which condition?

• A. High intravascular volume
• B. Low intravascular volume
• C. Normal intravascular volume
• D. Venous obstruction

Answer: (B)

Jugular venous distention in the supine position reflects the pressure in the central venous system and right atrium. When intravascular volume is low, venous return to the heart drops and right atrial pressure falls, so the neck veins aren’t distended and may even appear flat. That absence of visible JVD therefore points to low intravascular volume. If there were excess volume, venous pressure would rise and JVD would be more likely to be seen; venous obstruction tends to cause backup and distention as well. So the finding fits hypovolemia best.