How to Apply a Tourniquet Correctly

by Brian Graddon August 25, 2022

When someone is bleeding profusely from a limb, and medical personnel are not present at the scene, knowing how to apply a tourniquet can help to stop blood flow to the wound and control bleeding until emergency medical services arrive. Limb injuries can happen anywhere, anytime as the result of an accident, gun wound, stab wound, or natural disaster, and life-threatening bleeding from these injuries can be fatal if quick, appropriate action is not taken within minutes.

Step 1: Call 911 and Locate a Bleeding Control Kit

The first things you should do when you come across an injured person are:

Check whether it's safe to approach.
Call 911 or send someone to call 911.

If a bleeding control kit or first aid kit is available, take out the gloves to protect yourself. Otherwise, sanitize your hands with alcohol before touching the patient.

Step 2: Locate the Wound

The next thing you need to do is find the bleeding injury. If the patient is conscious, reassure them, lay them down, and check them over to find the source of bleeding. To prevent the patient from panicking, encourage them not to look at the wound.

Head. If the wound is on the patient's head, apply direct pressure with an absorbent material such as sterile (regular) gauze or clean clothing.

Chest. If the wound is on the patient's chest, apply a chest seal (if available).

Abdomen. If the wound is on the patient's abdomen, apply pressure with an External Trauma Dressing (ETD) or other abdominal pad.

Extremities. If the wound is on the patient's arm or leg, apply direct pressure with compressed gauze, utilizing hemostatic gauze if available. If possible, try to pack the wound with the gauze while continuing to hold direct pressure, and check to see if bleeding stops or becomes controlled.. If applying direct pressure for several minutes doesn't stop the flow of blood, or the injury is inaccessible due to entrapment, explain to the injured person that you will need to apply a tourniquet and that it will hurt but is necessary to save their limb or even their life.

Step 3: Apply the Tourniquet

Tourniquets are available in all bleeding control kits but usually do not come in standard first aid kits. If you have a bleeding control kit, locate the commercial tourniquet. If not, you may need to create an improvised tourniquet from a towel or a piece of clothing that's at least a couple of inches wide (to avoid cutting into the skin) along with a pencil, small torch, pop stick, or stick to use as a windlass.

Because it takes skill to apply an improvised tourniquet properly, commercial tourniquets are recommended for lay rescuers. There are several types of commercial tourniquets available on the market, with the most popular including the:

Combat Application Tourniquet ®

SAM-XT tourniquet

SWAT-T (stretch, wrap, and tuck tourniquet)

Note: Makeshift or improvised tourniquets should only be used in instances of uncontrolled traumatic bleeding when other interventions are ineffective and no professional tourniquet is available. When improperly applied, an improvised tourniquet can cause additional harm to the patient, endangering their affected limb and even their life.

How to apply a tourniquet:

Uncover the wound. Tourniquets are best applied to bare skin to prevent them from slipping.
Secure the tourniquet. If using a commercial tourniquet, slip it over the injured limb and position it around 2 inches (5 cm) above the wound—between the wound and the heart. If there is a joint in the way, position it just above the joint. If you can't slip it over the wound, undo the loop and resecure it in the appropriate position. For improvised tourniquets, tie the cloth with a half knot 2 inches above the wound (or just above the joint).
Turn the windlass. On a commercial tourniquet, turn the windlass until the bleeding stops and secure the windlass in place. On a makeshift tourniquet, tie the second half knot over the makeshift windlass (pencil, stick, etc), then turn it until the bleeding stops, and secure it firmly in place by tying it to the limb with a bandage or another piece of cloth. Interestingly, the word "tourniquet" itself comes from the French tourner, "to turn," referring to the turning of the windlass.
Write down the time. Tourniquets should not be left in place for more than two hours, because they can start to cause muscle injury and skin necrosis and cause complete muscle damage (often requiring amputation) after six hours. Using a black marker, write the time the tourniquet was applied on the white label on the commercial tourniquet or on the person's forehead: "T: TIME."
Make the patient comfortable. While you wait for medical personnel to arrive, put something soft under the patient's head to keep them comfortable, elevate the injured limb, and monitor them for signs of shock. Leave the tourniquet visible—don't cover it—so that EMS personnel can see that the person has a tourniquet. Don't remove or loosen the tourniquet because life-threatening bleeding could resume. The medical staff will remove the tourniquet in the hospital when it's safe to do so (in some cases, surgery is required to stop the bleeding).

Common Mistakes When Applying Tourniquets

These common mistakes can make the tourniquet ineffective or cause unnecessary damage:

Using a tourniquet when it's not required. Tourniquets should only be used in an emergency situation when direct pressure is not enough.

Not tying the tourniquet tight enough. Full occlusion is required to cut off the blood supply to the wound.

Not applying a second tourniquet. To be effective, a tourniquet needs to achieve complete occlusion, cutting off the blood supply completely (or close enough). If one tourniquet isn’t enough, apply a second one just above the first.

Not keeping the tourniquet tight. If the tourniquet loosens, traumatic bleeding could restart, leading to shock and potential death from blood loss. If you see rebleeding, retighten the tourniquet immediately and secure the windlass.

Leaving the tourniquet on too long. Leaving a tourniquet on for longer than two hours can lead to muscle, nerve, and skin tissue damage. Ideally, to prevent complications, tourniquets shouldn't be left on for much longer than an hour.

Using inappropriate material for the tourniquet. Hard materials like cord, string, dental floss, and wire can cause severe damage to the patient's skin and should be avoided. Ties can be effective but cause a ligature effect. Belts aren't soft enough to allow turning with a windlass. If you don’t have a commercial tourniquet from a bleeding kit, a wide band of clothing can be used, ideally with the help of professional medical advice, such as a paramedic giving instructions over the phone. Avoid using fabrics that overly stretch, such as spandex.

Taking the tourniquet off yourself. As soon as you take off the tourniquet, life-threatening bleeding can resume. Leave the tourniquet on and let the paramedics handle the rest.

Knowing How to Apply a Tourniquet Could Save a Life

Relatively few people know how to apply a tourniquet or are nervous to use them because of potential complications. However, in an emergency, a properly applied tourniquet can mean the difference between life and death.

Having a bleeding control kit on hand with a commercial tourniquet is the best way to be prepared to treat traumatic bleeding safely and effectively at home, at work, or on the road.

Article written by

Brian Graddon

Brian is a former Firefighter Paramedic who also worked as a SWAT Medic, Engineer, and Captain over a 15-year career. Brian is devoted to providing life-saving information based on his first hand experience in life-saving application of tourniquets, hemostatic gauze, chest seals and other bleeding control products.