This is the Combat Application Tourniquet (C-A-T). Note the stick you can use to wind the tourniquet tighter.

This is the Combat Application Tourniquet (C-A-T) by North American Rescue ($28.99*). Note the stick you can use to wind the tourniquet tighter.

by James Hubbard, MD, MPH

A tourniquet seems so simple. At its most basic, it’s just a strip of strong material.

Its use seems simple too. You tighten it until the bleeding stops. Voilà. Life saved.

But thanks to studies conducted over the last several years, the guidelines on tourniquets have become more sophisticated, causing emergency professionals to change how they use these lifesaving devices.

Here’s the latest thinking, according to the research I’ve been reading. I’m eager to also hear from you if you’ve used a tourniquet in the field. What have you found works or doesn’t?

How Quickly to Use a Tourniquet

In the vast majority of injuries, applying direct pressure to stop the bleeding is the way to go. But in cases where this doesn’t work, experts are increasingly advising that tourniquets should be used more often and applied quicker than they have been. Studies done during the last several wars have shown that tourniquets are more unlikely than previously thought to cause serious arm or leg damage.

Research has also found that the earlier a tourniquet is used, the more blood loss is averted, giving the person a better chance for survival. That seems obvious, but the message is just don’t delay, trying this and that and hoping and waiting. If someone needs a tourniquet, go for it.

The Medical Complications of Tourniquets

These updated guidelines by no means imply tourniquets are perfectly safe and you should use one on your next paper cut. Serious problems can occur.

Even with proper use, a small percentage of people who have used a tourniquet will end up with some nerve damage—pain, or partial to full paralysis of the area. Sometimes this lasts for several months and goes away. Other times it’s permanent.

And make no mistake. Cutting off blood supply for many hours can result in losing a limb.

On the other hand (pun not intended), when a tourniquet is needed—when there’s a lot of blood loss from an extremity and direct pressure is not working—the sooner you use one, the more chance you have of saving a life.

By far, most of the time, most of the damage to a limb after tourniquet use is from injury-caused damage to the arteries and nerves rather than from the tourniquet.

The Benefits of Commercial Tourniquets

Though there are various ways to make a homemade tourniquet, many experts are saying you should have a commercial tourniquet in your emergency kit. Nothing works as well or is as reliable because due to muscle or fat or whatever, getting a big artery to stop bleeding can be harder than you might think.

A Combat Application Tourniquet (C-A-T) type (pictured above) has supportive studies behind it. And it can be applied with one hand. Consider buying one, maybe two (one to keep in the car). Be sure to take it out of the package and practice. (You can tighten it until the pulse stops in an arm or leg. Loosen it immediately afterward when you’re just practicing, of course.) Know how it works before you need it.

Guidelines for Makeshift Tourniquets

Saying a commercial tourniquet is best is well and good, but my experience is that emergencies often happen when and where you least expect them. Say you’re hiking and someone falls or you’re in a crowd and a bomb goes off (I can’t imagine giving that as a likely scenario 20 years ago). You need to know how to make a tourniquet with what’s available. You can get a great idea of what a good one looks like by looking over the commercial brand.

The ideal makeshift tourniquet is one that’s most likely to stop the bleeding and least likely to cause damage. Here are some highlights of what recent studies have shown us about making one. (If you’ve used a makeshift tourniquet in the field, please comment. I really would like your real-life experience feedback on this.)

  • It’s important that the material is a minimum of one-and-a-half inches wide. If it’s narrower, it just doesn’t put enough pressure through all that flesh to the artery. If you only have narrow materials, consider using them anyway, and if the tourniquet you make with them doesn’t stop the bleeding, add another tourniquet adjacent to it.
  • The tourniquet material and the stick used to twist the tourniquet tight must be strong. Studies have shown that if either breaks during tightening, making you have to start over, your chance of stopping the bleeding is reduced.
Updated Guidelines on Using a Tourniquet

Here’s what research is showing us about how to apply a tourniquet:

  • Get as little slack as possible in the tourniquet before you begin tightening. This increases your chance of stopping the bleeding. Even with a commercial tourniquet it has been found that if you’ll make sure the material has no loose areas or gaps between it and the skin when you begin to tighten, you’ll likely have more success. I think this is where a lot of critics of using belts have a good point. Some belts are stiff. As long as the material strong, it’s best if it’s very flexible.
  • Applying the tourniquet just proximal to the injury (on the side toward the heart rather than the toes or fingers) stops the bleeding as well as or better than applying it up higher in the extremity. In other words, if the injury is in the mid-calf, apply the tourniquet between the calf and the knee, not up on the thigh.
  • One way to limit tissue damage is to initially not tighten the tourniquet more that you must to stop the bleeding. The more you tighten beyond that, the more you’re going to damage the tissue under the tourniquet just from direct pressure. This can result in needlessly killing fat and muscle. In addition, the damaged tissues can swell so much that it causes a permanent tourniquet (compartment syndrome) that can only be loosened by having a surgeon cut all the way to the bone to relieve the pressure.
How Long to Keep a Tourniquet On

To try to prevent damage to the limb, the advice used to be to loosen the tourniquet periodically to allow blood to circulate. Experts have changed their tune on that.

Now, they advise that if you get the bleeding stopped, you should keep the tourniquet on. There’s good proof that leaving it in place for two hours usually won’t cause permanent damage that wouldn’t have happened otherwise. And there’s good proof that loosening it periodically actually may decrease the chance of long-term survival.

Many experts are suggesting that, in most cases, even leaving a tourniquet on for several hours is more unlikely to cause permanent damage than previously thought.

But at some point, after six or eight or more hours, the risk of permanent damage becomes higher. (I read of one instance of someone having a tourniquet on for 18 hours without any serious damage, but I doubt that’s the norm.) So, if help is not on the way, what can you do?

I have read something about, after many hours, slowing releasing the pressure—maybe a few twists every hour, then a few more the next—to see if any clotting has set in. Then tighten it back if the bleeding stops, or perhaps keep the same tension and add direct pressure.

Tourniquets save lives. Knowing a few tips can make them more effective and lessen the risk of tissue damage.


You may have noticed that much of this information is from what “I have read.” If you’ve used a tourniquet before with real-life experience, please chime in with your comments. Do you disagree with any of my observations? Can you add more tips? Do you have experience using a makeshift one that did or didn’t work? Please share.

*The tourniquet links are affiliate links. I have no relationship with North American Rescue, the maker of the C-A-T tourniquet.

You May Also Like: