Why does the area around a broken bone feel cold?


So long story short; I broke my toe. My whole left foot (the broken one) has been absolutely freezing in comparison to my right foot for the past few days. I don’t have a cast on or anything so I can feel my foot against my leg at night sometimes and it feels like I’m putting ice directly onto my leg whenever they touch. My right foot feels like a normal temperature and it doesn’t bother me at all to touch it against my leg. Apparently this is a pretty common thing for broken bones and when I went to the doctor one of the initial questions they even asked before going to do an x-ray was whether or not the area felt cold.

Why is this? Is it to reduce swelling in the area?

In: 1

You’re thinking of it as if it’s an intentional bodily response to an injury as some sort of way to help heal it better. I think it’s more of a side effect. As an extremity, your toes naturally get cold sometimes. The way we warm them up is by circulating warm blood to the area. Think when your feet are cold and you wiggle your toes to try to warm up. When you injure a body part you tend to stop moving it around which reduces circulation. Thus, your toe gets cold and stays cold.

Your body has many mechanisms to produce heat, but perhaps the most effective for the boney extremeties is the circulation of blood. Any disruption in circulation (including low blood pressure, veins/arteries constricting, etc) can lead to cold fingers and toes. Technically just because your toe is broken doesn’t mean the immune response in the vicinity hasn’t been triggered by ruptured vessels leadimg to swelling and inflammation. This can increase the pressure needed to force the same amount of blood through fewer available veins and arteries…
Edit: this is especially true if your leg is elevated as the heart and leg are designed to pump blood down the legs first

In most cases these injuries are often accompanied by instructions to rest, which means you have a lower blood pressure than someone active and your metabolism may slow in response to the injury/rest combination leading to an overall decrease in the temperature of your body (when this happens, the blood vessels in your arms and legs constrict to prioritize keeping your body and head warm).

Tldr: The decrease in metabolic activity from bedrest/injury-exhaustion makes you cold and the decreased blood flow due to injury as well as vasoconstriction from the decreased metabolism mean there’s less blood that’s less warm flowing through the surrounding areas