What color is blood that is flowing from a cut vein?

Blood that flows from a cut vein appears dark red and flows steadily. This is due to the way venous blood is oxygenated. Unlike arterial blood, which is bright red due to high oxygen content and is propelled through the arteries with each heartbeat, venous blood has a lower oxygen content as it returns to the heart, resulting in its darker appearance.

When a vein is cut, the blood flows steadily because the pressure in veins is lower than in arteries. This flow does not exhibit the spurting characteristic that is typical of arterial bleeding, which is associated with bright red blood due to its proximity to arteries and the force of the heart pumping it. The consistent flow seen in venous bleeding makes it crucial for responders to recognize the difference and respond accordingly, as the management and potential urgency can differ significantly between venous and arterial injuries.