A
tourniquet is a constricting or compressing device, specifically a bandage, used to control
venous and
arterial circulation to an extremity for a period of time. Pressure is applied circumferentially upon the skin and underlying tissues of a limb; this pressure is transferred to the walls of vessels, causing them to become temporarily
occluded. It is generally used as a tool for a medical professional in applications such as
cannulation or to stem the flow of traumatic
bleeding, especially by military medics. The tourniquet is usually applied when the patient is in a life-threatening state as a result of continuous bleeding.