What causes corns?
Corns and calluses are caused by pressure on the affected area of your feet which causes the skin to harden to protect the softer skin underneath. The size, shape and level of pain associated with your callus or corn can vary depending on where it is and how much pressure the area is under, as well as other factors.
When we talk about pressure in this context, we’re referring to the physical stress applied to your feet day in and day out. Your feet go through a lot over the course of 24 hours – and you often don’t realise how much you take them for granted until they hurt. So, what sort of things can cause increased pressure on your feet?
Potential causes of corns and calluses on your feet include but are not limited to:
- Ill-fitting shoes – shoes that are too tight will exert pressure on the edges of your feet
- Wearing stilettos or other high-heeled shoes – this forces you to bear all your weight on the balls of your feet
- Spending a long time on your feet
- Performing intense exercise on your feet – for example, long hikes, running or jogging
- Having a reduced amount of protective fatty tissue on the sole of the foot – which happens naturally as you age
However, it’s not quite as simple as the idea that doing a certain thing will cause a corn to develop. Your likelihood of developing corns and calluses may in part depend on how unusual the circumstances are. For instance, if you’re training for your first marathon, you may be more likely to develop calluses than someone who runs regularly – this is because their feet have become better adjusted to intense exercise. That doesn’t mean, though, that people who habitually run a lot are immune to corns and calluses.
Another thing to consider is that rest and recuperation takes time. If you go for a long hike, and then head out for another on the next day, you may be more likely to develop corns or other foot problems than if you had a week of rest between hikes. This is because your feet aren’t getting as much time to recover from the initial exertion.
How do corns form on your feet?
In their natural state, your feet are soft and cushioned in order to protect the bones and muscles inside. The fleshy pads that make up the soles of your feet help to do this, but there’s only so much pressure they can be under before something has to change. When you put your feet under increased stress – such as in the situations outlined above – your skin starts to harden to try and defend the more vulnerable parts of your feet from damage.
These hardened areas – corns or calluses – act as a shield to prevent other injuries such as blisters or cuts. Injuries that open the skin are more susceptible to infection, so calluses help to protect against that by hardening the skin before it can be broken.
Although the outermost layer of your skin is the most likely to be damaged, corns typically have a hardened portion that goes deeper into your foot. It’s sometimes referred to as a root, similar to that of a plant, or the root of a tooth. The hardened root of a corn can cause discomfort when you walk on it, making it harder for you to get on with your everyday activities.
How to avoid getting corns on your feet
If you’re looking to avoid getting corns, you might have heard that the only way to do so reliably after having one is to remove the corn with its root attached. It’s tempting to believe that removing the whole thing will stop the problem from returning, but this isn’t always the case. The only way to prevent a corn from forming, regardless of whether or not you’ve had one before, is to relieve the pressure on your feet.
One way you could do this would be to not put excessive pressure on your feet in the first place. Unfortunately, this isn’t always easy or possible to do. For example, if your job requires you to be on your feet all day, putting stress on your feet is inevitable. So, if you can’t avoid the activity that puts pressure on your feet, what can you do?
The answer is to spread that pressure rather than avoiding it. In the vast majority of cases, you don’t get a corn that spans your whole foot, even though your whole foot has been under pressure while you run a race or walk around all day. More commonly, a corn forms in an area that has been particularly under pressure, whether that’s because of the fit of your shoes or the way that you walk or something else entirely. Corns develop in places where the pressure is most concentrated because the burden of your body weight isn’t spread evenly across the soles of your feet.
The solution to this is to use a pressure-relieving insole to spread the burden more appropriately and deflect pressure away from the painful corn or callus. Some insoles do this by using raised sections and lowered sections to redistribute your foot within your shoe. By having a small dip under the area that’s been under most pressure, the rest of your foot is forced to take up the weight instead, thus alleviating the strain on the affected area. This reduces pain, allows your corn to heal and helps to ensure that you don’t develop more calluses in the future.
