Why do a wound bleed?

Bleeding, or hemorrhage, is the loss of blood from a blood vessel. It can occur internally or externally, and it can be caused by trauma, surgery, or other medical conditions.

There are three types of blood vessels: arteries, capillaries, and veins. Arteries carry oxygenated blood away from the heart and to the rest of the body, while capillaries are tiny vessels that allow oxygen and nutrients to pass through their walls into the surrounding tissue. Veins carry deoxygenated blood back to the heart.

When a blood vessel is damaged, the flow of blood is interrupted. This can cause a number of problems, including:

* Oxygen deprivation: When the blood supply to a tissue is cut off, the cells in that tissue no longer receive oxygen. This can lead to cell death and tissue damage.

* Blood loss: Severe blood loss can lead to shock, a life-threatening condition.

* Infection: A break in the skin can provide an entry point for bacteria, which can lead to infection.

* Scarring: When a wound heals, it often leaves behind a scar.

Bleeding is a normal part of the healing process. However, excessive bleeding can be a sign of a more serious medical condition and should be evaluated by a doctor.