Why Do Some People's Thighs Chafe

Why Do Some People's Thighs Chafe

Posted by Jack Miller on 18th Apr 2022

If you've ever wondered why some people's thighs rash and yours don't, don't worry. You're not alone! Chafe can be a really frustrating condition because it happens when we do things that are good for our health, like exercising or even just walking around on a hot summer's day.

The best news is that chafing doesn't have to hold you back from doing things that are good for you. With the right preventative steps, you can stay active and comfortable. Let's get started on understanding chafing!

What is chafing?

Chafing is a skin irritation that happens when your thighs rub together because of friction when they move. This rubbing causes redness and pain in the area between your inner thighs (the groin). It usually happens during activities like walking, jogging or riding a bike—but it can also happen just sitting down in tight pants or skirts.

Excessive rubbing

You're not alone in your chafing woes. Chafing can happen to anyone who has skin, and it happens when two surfaces rub against each other harshly. This harsh rubbing can cause friction or heat, which causes the top layer of skin (the epidermis) to separate from the bottom layer of skin (the dermis). The result is pain and redness.

Chafing can happen anywhere on the body, but it's most common in areas with folds of skin that rub together: inner thighs, underarms, sides of breasts, nipples and back. It's also possible for chafing to occur between your thighs and clothing or between your thighs and furniture like a car seat or couch cushion.


One of the reasons your thighs chafe is friction. Friction is the resistance that occurs when two objects rub against each other. It creates heat, which can lead to skin breakdown. This means that the more you move, the more friction will occur between your two legs. As a result, this causes your thighs to chafe


Heat is your body’s natural cooling system (among other things). When you put in physical effort, your body temperature rises and blood vessels dilate to release heat. This is why you become red in the face when you run, or feel warm after an intense workout session.


Humid weather increases the moisture on your skin and in the air, which means that you’re more likely to sweat—which adds even more moisture, resulting in a recipe for chafing. While sticking with breathable fabrics like cotton may help keep things cooler (and drier), conditions can still get pretty steamy if you spend any time exercising outdoors.

Certain fabrics

If you’re prone to chafing, certain fabrics can cause more irritation. Avoid lanolin and wool; in dry climates, these fabrics will feel prickly and scratchy against your skin. In humid climates, they can become damp and heavy with sweat, causing even more friction. Instead of wool or lanolin, opt for a synthetic material that wicks moisture away from the body. Polyester “cool-max” running gear is great for this purpose, it is good to use for chafing underwear and will create a protective barrier for your thighs.

On the flip side, some colours of synthetic fabrics can be irritating as well. Dyes are often added to polyester clothes to make them an array of colours—and these dyes can cause or worsen chafing in sensitive people. The best advice? Choose cotton underwear or gear made from 100 per cent cotton fibres—or undyed cooling materials such as polyester.