When to Apply a Tourniquet – Our Full Guide

A person who has suffered a severe injury can bleed to death in a matter of minutes without first aid. Emergency help should be called immediately if someone is experiencing heavy blood loss. If the bleeding cannot be stopped by applying direct pressure, first responders may need to use a tourniquet to prevent further blood loss.However, it is important to know when to apply a tourniquet as it comes with some risks and should only be used when necessary. Read on to find out how and when to use a tourniquet properly.

What is a tourniquet?

A tourniquet is a device that is wrapped tightly around a person’s limb to prevent blood from flowing to the limb for a short period of time.Tourniquet use is designed to control life threatening bleeding on patients who are suffering acute blood loss from a wound on their arm or leg.

When to Apply or Use a Tourniquet

Tourniquets are used when there is major blood loss or hemorrhaging from a wound on the arm or leg. They should only be used in life threatening situations.They are an alternative option for controlling blood loss if direct pressure is not enough or if direct pressure is not possible, such as if the wound is inaccessible, if there are multiple casualties or if there are multiple injuries that need immediate attention.Examples of situations where a tourniquet might be used include car accidents, deep cuts, crushed limbs and gunshot wounds.Tourniquets cannot be used for injuries to the head or torso regions. They should also not be used if the bleeding can be controlled by direct pressure.

What are the risks of using a tourniquet?

The use of a tourniquet can be potentially life saving, however it should only be used if necessary as there are a number of risks involved.Tourniquets work by restricting blood flow to the affected limb, which means limb tissues like skin, muscle and nervous tissue no longer receive oxygen. This can cause serious tissue damage and even tissue death. The use of a tourniquet may lead to amputation.

How to apply or use a tourniquet

The steps below explain how to use a tourniquet if someone is suffering from high blood loss due to a wound on their arm or leg. Severe bleeding is a medical emergency and you should call 000 immediately for help.

Step 1. Examine the wound site

Sit or lie the patient down, whatever is most appropriate for their limb injury. If possible, raise the affected limb above the level of the heart.Examine the wound to discover the source of the bleeding and how heavy the blood flow is. If there are any foreign objects inside the wound, remove these carefully as they may be contributing to the bleeding. Do not attempt to remove any deeply embedded objects.

Step 2. Apply pressure to the wound

If this stops the bleeding, continue to apply pressure for 10 minutes to allow blood clots to form.Once the bleeding is controlled, apply a dressing to the wound. If the wound bleeds through the dressing, apply a second dressing.If the wound continues to bleed through the dressing, consider using a tourniquet. If appropriate, apply the tourniquet as quickly as possible to avoid further blood loss.

Step 3. Position the tourniquet

Before tourniquet application, make sure you explain to the patient what you are doing and why.Remove any clothing away from the wound so that the tourniquet can be applied to bare skin if possible.Position a commercial tourniquet or an appropriate improvised tourniquet about five centimeters or more above the wound, but not on a joint such as the knee or elbow.

Step 4. Tighten the strap and twist the handle

Tighten the tourniquet and then begin twisting the handle (also known as a windlass) to increase the pressure.Keep an eye on the wound and observe if the bleeding slows or stops. You should stop winding the handle when the flow of bright red blood stops or slows significantly.Lock the handle in place to prevent it from unwinding.

Step 5. Write down the time

Note down when the tourniquet was applied. Medical staff and first responders will need this information as tourniquets should not be applied for long periods of time.Tourniquets should only be removed by medical personnel. 

Medical grade tourniquets vs homemade tourniquets

Purpose made medical grade tourniquets are preferred over homemade or improvised tourniquets as they are a more reliable and effective means of preventing blood loss.However, if a medical-grade tourniquet is not available, improvised tourniquets can be used if necessary.Examples of items that can be used to create an improvised tourniquet include belts, torn clothes, scarves, neck ties and bandages. Do not use materials that are thin, like wire, cord or shoelaces, as these can cause nerve damage and are less effective at stopping severe bleeding.Knot a straight, rigid item like a stick, jack handle or broom handle in the outside layer of your tourniquet to use as the windlass. 

When to use a tourniquet vs pressure

A tourniquet and direct pressure are both used to control bleeding, but knowing when to use each is critical. Direct pressure is the first-line method for most bleeding injuries—applying firm pressure with a clean cloth or bandage over the wound helps stop blood flow. This method is effective for minor to moderate bleeding and should always be attempted first.A tourniquet, on the other hand, is a last resort for life-threatening bleeding, typically from limb injuries where direct pressure is not enough. It should be applied about 5 cm above the wound, tightened until the bleeding stops, and noted with the time of application. Using a tourniquet incorrectly or unnecessarily can cause tissue damage, so it’s reserved for severe cases, such as traumatic amputations or deep lacerations where blood loss is rapid and uncontrolled.

Uses and Importance of tourniquet

• Emergency Bleeding Control – Used in trauma situations where severe bleeding from a limb cannot be controlled with direct pressure.

• Trauma and First Aid – Essential for life-threatening injuries like amputations or deep lacerations.

• Surgical Procedures – Helps create a bloodless field for improved visibility and precision during operations.

• Medical Procedures – Temporarily applied during blood draws or IV insertions to make veins more accessible.

• Military and Tactical Use – Used by soldiers and first responders in combat or disaster situations to prevent fatal blood loss.

• Industrial and Workplace Safety – Included in high-risk work environments (e.g., construction, manufacturing) for emergency use.

Note: Prolonged or incorrect use can cause nerve and tissue damage, so tourniquets must be applied with caution.

Where to buy tourniquets and trauma kits

When a traumatic injury occurs, it is important to be prepared with the right first aid equipment and training – that includes knowing when to apply a tourniquet and how to do so effectively.At LFA First Response, we understand the need to be prepared so you can respond quickly and effectively when there’s a need. We stock a wide range of medical-grade first aid supplies, including tourniquets, wound dressings, trauma kits, snake bite kits and more.Order online today or get in touch with our friendly customer service team to discuss your needs.