Why do people die from internal bleeding?

Question

Let's say you have a ruptured artery in your brain. Most people die quickly from that. My question is exactly how do you die from that? The blood is still contained inside the body, and not necessarily lost, or so it seems to me. Once while have my blood drawn, the vein burst. Obviously I'm alright and wasn't in immediate danger. So why was it ok for it to burst in my arm? I hope this isn't too vague, I'm just curious as to what goes on during internal bleeding.

Answer 1

In the brain its due to pressure build up and lack of oxygen upstream from the "bleed". In the rest of the body blood clots can cause you to die because if the blood is not in your blood stream (arteries and veins) its not going to the heart to be circulated, and its not going to the lungs to be oxygenated (lack of oxygen to vital organs/tissues). All kinds of problems with internal bleeding, having your blood drawn and having a vein "burst" is not really considered internal bleeding its so small, its like getting any other bruise and you dont die. Its easy for the body to recover from small bleeds depending on where they are. Hope this helps

Answer 2

A small amount of blood isn't a big deal. It will just get reabsorbed. When a vein bursts from a needle stick it reseals itself almost immediately and the bleeding stops. With a large blood loss--the blood is no longer in large amounts in the vessels. This causes the blood pressure to drop-- there isn't enough force behind the heart pumps to circulate the blood fast enough, so the oxygenation cycle -- lungs/heart slows down and you die.

Answer 3

The biggest problem internal bleeding poses is the disruption of normal organ function.  Internal bleeding can cause the blood to become compacted against the organ, making it work twice as hard but get less than half of the desired effect.  That right there should show you why it was okay for your vein in your arm to burst... no organs near it :)