Hot cold therapy – how it works

hot and cold therapy - swollen ankle

Are you confused about when to use hot and cold therapy in the treatment of musculoskeletal conditions or do you want to know just a little bit more about how hot cold therapy works?

Here we explain what the effects of hot and cold are on the body and why at certain times the use of heat and cold can be beneficial in the treatment of muscle and joint aches and pains.

How the blood vessels work

One of the things that we know is that the vessels that supply blood to our muscles and other parts of our body are active, they are muscular, so the arteries for example contract and expand at various times and in varying conditions.

When an artery expands we call that vasodilation, the diameter of the circumference of the vessel increases and allows more blood to pass through it. In other circumstances the opposite is true and at certain times of the day it may be necessary to vasoconstrict, where the vessel becomes smaller in diameter. The brain monitors the blood pressure in our bodies continuously as well as core temperature so when these mechanisms become out of balance the brain takes steps to correct them.

The Endothelial cells, which is the muscular lining of the vessel, in a constricted state are squeezing and reducing the diameter of the blood vessel. When the opposite happens in a dilated blood vessel, the homeostatic mechanisms of the body may have become out of balance and there’s a need to allow more blood flow through to the area that’s being supplied by the artery.

When to use hot cold therapy

Under normal conditions the brain does a very good job of maintaining the internal balance using a mechanism called homeostasis but occasionally there will be situations where that mechanism doesn’t work properly and it has a detrimental effect on the functioning of the body or the tissues.

In that situation it may be useful for us to use either hot or cold therapy to influence vasoconstriction and vasodilation. We might use a cold pack or an ice pack for example to influence vasoconstriction and to create a mechanism for squeezing down the arteries and reducing blood flow.

In other situations we might require the use of heat to influence vasodilation, so we might use a microwaveable heat pack to dilate the blood vessels and increase blood flow.

The circumstances in which you might use either hot or cold treatment for your muscle and joint pain are outlined in our Hot cold treatment – When to use blog post.

Treatment with heat and cold

If you’re experiencing any muscle or joint pain use our pain assessment feature to find the cause. Our treatment guides explain how to use hot cold therapy in the treatment of musculoskeletal conditions.

Start your free assessment

Watch the hot cold therapy video here

Other resources

Treating pain with hot and cold
Heat and cold treatment: Which is best?