How Tight Should a Tourniquet Be?

If you ever have to apply a tourniquet, it's important to know how tight the tourniquet should be. If a tourniquet is too loose, it won't stop the bleed. If it's too tight, it could cause unnecessary damage.

A tourniquet should be tightened until the bleeding stops. In general, you should not be able to fit your fingers underneath the tourniquet. Another way to tell if the tourniquet is tight enough is to check the pulse beyond the injury to ensure that it is absent. When you are trying to stop a life-threatening bleed, you generally want to worry more about the tourniquet being too loose than too tight.

There are many nuances to this subject. Sadly, this is one of those times where if you get it wrong, people will suffer.

How Do I Know When a Tourniquet is Tight Enough?

In this section, we'll give you several ways you can know that a tourniquet is tight enough. It's not always easy to tell, so it's wise to have multiple methods of measuring tightness. There are also multiple parts of the tourniquet that need to be tight (the initial strap, and the windlass).

If you're totally new to tourniquets, don't worry. We'll explain everything in detail and provide links to other articles that provide more depth when needed. Ultimately, our goal is to stop dangerous bleeds and ensure that people are confident when applying a tourniquet.

Here's how you know a tourniquet is tight enough:

• The bleeding stops completely
• The tourniquet cannot be tightened anymore
• The pulse has stopped below the injury
• The person feels the pressure and pain
• Sometimes, a tourniquet can be overtightened (especially when there's a lot of adrenaline)
• You MUST avoid a cheap tourniquet
• Some tourniquets work differently than others (the SAM and the SWAT)

Now, we'll provide more details on each of these points. Also, if you're curious, see our article on when to remove a tourniquet (if at all!).

How to Know a Tourniquet is Tight Enough: The bleeding stops completely

The most basic way to know when a tourniquet is tight enough is to see if the bleeding as stopped. If the bleeding has stopped, then you know that the tourniquet has done its job and it does not need to be tightened anymore.

Sadly, there is no exact "number" when it comes to how tight a tourniquet should be. Certainly, tourniquets could have little pressure gauges on them that tell you when you've reached a certain tightness, but this would be essentially useless. Why?

Because different people require different tightness. For example, a body builder is going to require much more pressure from a tourniquet than a young child. If you were to apply the same amount of pressure to each, either you would snap the child's leg clean off (nearly), or you wouldn't stop the blood flow of the body builder.

For this reason, there is no secret number of tourniquet "twists" required to stop a bleed, rather we have to look at the patient to see if it's working. So, the simplest way to know if a tourniquet is tight enough is to ensure that the bleeding has completely stopped!

However, what if it's dark outside? Or what if there is so much blood you can't tell if the tourniquet has stopped the bleeding? Well, there are other methods.

How to Know a Tourniquet is Tight Enough: The tourniquet cannot be tightened anymore

The next way to know if a tourniquet is tight enough is if you can't tighten it anymore. Now, this comes with caveat. First, you want to be honest with yourself about how tight you are able to tighten the tourniquet.

Remember what we said about the body builder? They will likely be able to keep tightening a tourniquet forever - and one of two things will happen. First, the tourniquet may snap (this has happened), or the person's limb may snap. Either outcome is bad.

So, what do you do? If you're a relatively strong person, it may seem like if you really wanted to, you could give that tourniquet one more twist. Well, what you do is use good judgement. You tighten the tourniquet until it won't tighten anymore, leaving out the fact that if you went all hulk-mode on the tourniquet, you might be able to get one more twist (and risk injuring the patient or breaking the tourniquet).

If the tourniquet has been tightened all the way and the person is still bleeding, instead of going "hulk mode" and trying to get one more twist, it would be better to apply a second tourniquet above the first. This will almost always stop the bleeding.

How to Know a Tourniquet is Tight Enough: The pulse has stopped below the injury

Remember what we said earlier about not being able to tell if the bleeding has stopped? It some cases, there is so much blood, it's hard to tell if the bleeding has truly stopped. In this case, there's a little trick you can implement to tell if the tourniquet is doing its job.

Let's say someone is bleeding from just above their elbow. It's a lot of blood. You apply a tourniquet just below their shoulder, but you can't tell if the bleeding has stopped. What do you do? You can feel for a pulse in their wrist just below their thumb (called the radial pulse). If there is no pulse here (and there was one before), then there's a pretty good chance you've stopped the bleeding.

How to Know a Tourniquet is Tight Enough: The person feels the pressure and pain

One of the sad parts of tourniquet applications is that it is usually quite painful. This can be a major hurdle, as sometimes the tourniquet is more painful than the injury. What can happen is that, as you apply the tourniquet, the person with the injury can start yelling, "No! Stop! It hurts!" What happens?

The rescuer stops tightening the tourniquet because it hurts, and now the person bleeds out. Not good. This is why it's vital to explain to people before you place a tourniquet: "this is going to really hurt, but it will save your life." You can also assure them that medics can usually give them strong pain medications for the tourniquet after the ambulance arrives.

So, even though it's a shame, if the person complains that the tourniquet is too tight or that it really hurts, you probably have it tight enough. If they say that they don't feel it, or that it's not that uncomfortable, then it may not be tight enough.

Note: there are some tourniquets that hurt worse than others. The SWAT-T is a rubber-based tourniquet that is quite wide, and it does not usually hurt as bad as others. NEVER use a tourniquet that is too thin (like a piece of cord thin rubber band). These tourniquets require much too much pressure and are not approved for use by many EMS services or military units.

Bonus: Sometimes, a tourniquet can be overtightened (especially when there's a lot of adrenaline)

You have to use good judgment when apply a tourniquet. You want it to be as tight as needed, but you don't want to go hulk crazy. This is especially true if you're applying a tourniquet to someone who is smaller, or a child.

What can happen if you overtighten a tourniquet? Well, you can break the tourniquet (especially a cheap or fake tourniquet), or you can cause unnecessary damage. With that said, many tourniquets are not tight enough, so if you're not sure, err on the side of a little too tight than a little too loose.

There are some people who will say that you can't overtighten a tourniquet; however, as you can see, there is more to it than that.

Bonus: You MUST avoid a cheap tourniquet

Never buy a knock-off brand tourniquet. Stick to the major brands and be sure to confirm that they are the real deal. There are a lot of cheap and fake tourniquets floating around on Amazon and other sites, and these are almost worthless. They break even when tightened to normal pressure, and do not reliably stop bleeds.

For the most part, a good tourniquet will cost at least $30 PER TOURNIQUET. If you find a "3 pack for 30 bucks" then you've almost certainly found a cheap pack of counterfeits. Hey, if you want to buy a counterfeit watch, fine––but don't cheap out on something designed to save a life.

Bonus: Some tourniquets work differently than others (the SAM and the SWAT)

Not all tourniquets have the same design. Remember what we said about the two different ways you need to tighten a tourniquet? Before you use the windlass, you have to tighten the strap around the limb.

This is the part that many people get wrong. If you don't tighten the initial strap, then you're going to have a hard time when you go to tighten the actual windlass. The SAM-XT tourniquet has solved this problem with an intuitive "click" system. Basically, it clicks into place when the initial strap is tight enough, and then you know you're ready to spin the windlass.

THE SWAT-T is a rubber-band tourniquet that is made to be wrapped and steadily tightened around the limb. This one has no windlass but can be a good choice for children.

Conclusion: How to Make Sure a Tourniquet is Tight Enough

To ensure your tourniquet is tight enough, first check that all the bleeding has stopped. Then, confirm that there is no pulse below the injury. Finally, if the tourniquet does not hurt, then it's likely not tight enough.

Remember, never buy a fake tourniquet. Also, get trained, practice, practice, and then practice some more. You never know when your skills will save someone's life. Or your own.

If you're curious, take a moment to look at our article that asks the question: when do tourniquets expire?