You’ve probably heard, in the case of an injury, put ice on it. But, is that actually helpful? It’s kind of unpleasant, not to mention inconvenient. And for how long? And how often?

Here, I’m going to make the case for putting ice on it – why it’s worth it to put in all the effort, and deal with the discomfort and inconvenience – and give you the parameters for doing it.

With any injury to body tissue, big or small, blood vessels are torn. Torn vessels allow blood and damaged cells to leak out into the surrounding tissue where they don’t belong. This initiates an inflammatory process that is necessary for healing, and causes swelling, which is the accumulation of fluid in an area of the body. Stopping the bleeding is the body’s number one priority, so the process of clotting begins immediately and will go on for a few hours to a few days, depending on how much damage there is. The healing process cannot begin, until the bleeding has stopped.

It is much more difficult to patch a torn blood vessel with a blood clot if blood is coursing through at its usual rate. Anything that can reduce the speed or volume of blood flow will help the clotting process happen more quickly.

Ice is one thing that will slow the flow. The viscosity of blood, meaning the thickness, will increase as its temperature decreases, increasing the friction between the blood and the wall of the blood vessels, slowing the rate of flow. The body will automatically route more blood through other vessels to compensate for the slowing in the area experiencing a temperature decrease.

What’s so bad about blood being outside of blood vessels? Especially if it’s presence there is what initiates the healing process? 

1 – Delay

If the body is still working on damage control, it cannot start the healing process. If you stop the bleeding in 6 hours, instead of 30 hours, you have gotten a day’s jump on the healing process. 

2 – Clean up time

Blood and damaged cells outside of the circulatory system have to be cleaned up and taken out through the lymph system – the garbage. This process is amazing, but it takes time. So if less blood gets out, because the bleeding stopped at 6 hours instead of 30 hours, you will have less to get rid of as part of the healing process, which will save you days, depending on the severity of the injury.

3 – Clean up efficiency

The lymph system consists of small vessels leading to bigger vessels with the eventual destination being the kidneys, where it gets eliminated from the body. Blood and damaged cells in an area where they aren’t supposed to be put pressure on the smaller collector vessels, reducing their effectiveness at picking up the unwanted cells and shunting them off to bigger vessels.

4 – Pain

Pressure buildup from blood and cells in an area they aren’t supposed to be causes pain, due to it being a closed system.

5 – Lack of range of motion and muscle contraction efficiency 

Blood and damaged cells collecting where they’re not supposed to be limits the available range of motion of the closest joint/s, limiting function. It also doesn’t allow nearby muscles to contract normally or in their most efficient pattern. 

6 – Muscle spasm (a state of partial contraction)

The presence of blood and damaged cells in an area causes the surrounding muscles to go into protection mode, which means they stay partially contracted in order to limit function that would cause further damage. Muscle spasm causes pain, in addition to the pain already coming from damaged tissue.

The upshot of it all is TIME! Ice allows you to stop the bleeding faster. It allows the healing process to start quicker and proceed more efficiently by not having a lot of associated garbage to get rid of and the associated factors that slow the process. It also limits the amount of time spent experiencing pain and everyday dysfunction, as well as promoting circumstances that allow a return to full performance level more quickly.

It’s a win/win right?