Tourniquet

A **tourniquet** is a tightly-compressed bandage used to stop bleeding. A tourniquet does this by going hard and tight against the skin to compress the blood vessel, stopping the flow of blood through a large artery in a limb. Normally when a tourniquet is put on, it goes above the joint of the affected limb. 

It can be made from clothing or any tightly-compressible material in the case of an emergency. There are ready-made, tightly packaged tourniquets which can be carried in a bag or first-aid box. These professional tourniquets are useful for people who treat emergencies often because they are faster to use and are probably sterile. If a rag or piece of clothing is used then the cleanest one is usually found. There are many different types of tourniquet.  

## Use
In patients with major limb damage a tourniquet is used if direct pressure has failed to control life-threatening bleeding. The tourniquet goes on a limb as close to the joint (the knee or elbow) as possible, above the wound and the joint if possible. It is not safe to use one on the neck or around the body as this could stop the breathing or damage the organs. 

Once on they should not be covered or hidden by anything like clothing. Sometimes the person using it also writes one or two letters or some symbol on a treated persons forehead, in some settings and countries, to tell everyone that a tourniquet is applied to this person. They should not be removed except by a medical professional once on. This can damage (a type called reperfusion damage) the limb and may cause ischaemia. Having one on for too long or doing it for no reason can also cause damage, but sometimes it is the best option and has to be kept on despite the risks. 

## Forms/Alternatives
Alternatives are chemicals which stop bleeding, putting pressure on the wound, or the other types of bandages and different forms of the tourniquet, like the useful packing in some types which is used to cover more skin or make bandage tighter. The Israeli bandage (or "H tourniquet") is a very useful type of tourniquet which can be tightened easily. These have a piece to twist to make the bandage go tight against the skin, instead of pulling it which is more hard. Some may use  Coagulants or haemostatic chemicals, in powder form on a bandage or put straight on the skin. 

Powders and injectable drugs can be used in trauma response. These can stop bleeding with or without the help of a tourniquet quickly. One haemostatic agent that is used is intravenous tranexamic acid but some agents might be as simple as being the correct alkaline pH.

The bandages come in three sizes: 4, 6, and 8 inches wide.

The bandage was favorably reviewed in the *Military Medicine* journal.

## Death Triangle
The body loses heat when it loses blood (the blood is a tool that it uses for thermoregulation) in serious bleeding. Cold blood, compared to how warm blood normally is, is not as good. It does not clot as easy. The second part is acidity. In serious bleeding, the blood will become more acidic. The third part is losing the ability to form blood clots easily. When blood becomes more acidic, loses heat, and loses its ability to clot or coagulate on its own it is serious because it is on all three points of the danger triangle.

The body usually makes bleeding stop by causing clots, so being without coagulation makes clotting more difficult in 'normal' functioning patients. When the body can not do this it means outside forces need to help make the bleeding stop. This all means that bleeding is an important factor to keep track of and stop before it becomes more serious bleeding that gets worse as time goes on. 

## References