Have you ever woken up and discovered that you have some new, mysterious bruise on your legs or arms? Well, there's a simpler explanation than playing hockey in your sleep, and it's all in how your skin is structured. Photo by Lindsey Turner.
Some people, especially women, bruise easier than others. As dermatologist Dr Joel Cohen explains over at Vice, this usually happens when a person has less collagen in their skin. Your skin has several layers that, among other things, protects the blood vessels underneath from damage. If you have a thinner layer of collagen, you can bruise more easily:
Collagen is "the main structural building block in the skin." In the dermis, collagen forms a network of fibres that hold the rest of the skin together like a net. The collagen supports blood vessels so they are more protected from blunt force. Subcutaneous fat, on the other hand, does not structurally support the blood vessels -- it's padding. "It's part of our buffer before we get down to the bone," says Cohen. "It protects our bones and muscles from the outside world."
Bruises also show through more easily when you have a thinner layer of collagen. While it can vary from person to person, women tend towards having a thinner collagen layer than men, which can result in light bruises happening more frequently. While bigger bruises still mean bigger trauma and shouldn't be ignored, light bruises can occur from even small bumps that you'd otherwise ignore.