It’s one of the more puzzling things people bring to a podiatry appointment. Both feet do essentially the same job, cover the same ground, and live in the same shoes, so why does one hurt and the other feel perfectly fine?
It’s a great question, and the answer is rarely “just bad luck.” There’s usually a reason one side is bearing more than its share of the load, and understanding that reason is often the key to actually fixing the problem rather than just managing symptoms.
Here are the most common explanations.
Your two feet are not identical
This surprises a lot of people, but it’s completely normal for feet to differ from one another. Most people have one foot that is slightly longer, wider, or sits at a slightly different angle than the other. One arch might be a little lower, one heel a fraction wider, one set of toes a bit more crowded.
In many cases, these differences are small enough that they never cause problems. But when one foot has a structural quirk, like a lower arch, more pronation, or a slightly different alignment through the ankle, it can mean that side consistently absorbs load differently. Over time, particularly with increased activity or less-than-ideal footwear, that small asymmetry can translate into one-sided pain.
This is also why shoes sometimes wear unevenly, it’s not because one shoe is defective, but because the two feet it’s covering are doing slightly different things.
Limb length differences
Even a small difference in leg length, sometimes just a few millimetres, can shift how the body distributes weight. The longer leg tends to bear more load through the hip and knee, while the foot on the shorter side may pronate more or be held at a slightly different angle to compensate.
Limb length discrepancies are more common than most people realise and often go unnoticed for years. They tend to become more apparent when someone increases their activity level, changes their footwear, or starts a new exercise routine. This is because the asymmetry that the body was quietly managing suddenly has more load to cope with.
A podiatrist can assess for limb length differences as part of a gait assessment and, where relevant, recommend footwear modifications or orthotics to help even things out.
A previous injury on one side
This is one of the most common reasons for persistent one-sided foot pain, and it’s not always obvious to the person experiencing it.
An old ankle sprain, a stress fracture that healed years ago, a period of compensating after a knee or hip injury, all of these things can leave behind subtle changes in how the foot and lower limb move. Ligaments that were stretched may not have fully regained their original stability. Muscles that were protecting an injured area may have stayed in a guarding pattern long after the injury resolved. The foot may have learned a slightly different movement pattern to avoid pain and simply kept it.
People often don’t connect current foot pain with something that happened years earlier, particularly if the original injury felt like it healed well. But the body has a long memory, and old injuries have a way of quietly influencing things long after they’re forgotten.
Muscle imbalances and movement patterns
The foot doesn’t work in isolation. How load travels through it is influenced by what’s happening further up the chain, through the ankle, calf, knee, hip, and even the lower back.
Weakness or tightness on one side of the body, like a hip that doesn’t extend as well, a calf that’s tighter on the left, a glute that’s less active on the right, can alter how weight is distributed with every step. Over thousands of steps a day, those small asymmetries in load add up.
This is one of the reasons that foot pain sometimes responds better to rehabilitation that addresses the whole lower limb rather than just the foot itself. If the source of the asymmetry is higher up, treating only the foot tends to provide limited or temporary relief.
Dominant side loading
Most people have a dominant side, a leg they instinctively lead with, push off harder from, or favour during activity. For right-handed people, this is usually the right leg, though it’s not universal.
The dominant leg tends to be slightly stronger and more heavily loaded across a range of activities, from sport and exercise to everyday movements like climbing stairs or getting up from a chair. Over time, this can contribute to one-sided wear and tear, particularly in the structures that take the most impact, like the heel, the plantar fascia, the Achilles tendon, and the big toe joint.
It’s rarely the sole explanation for foot pain, but it’s often a contributing factor, particularly in active people.
Footwear that fits differently on each foot
Because feet often differ slightly in size and shape, a shoe that fits well on one foot may not fit quite as well on the other. The foot in the slightly tighter shoe may be more prone to nail problems, blisters, and forefoot pain. The foot in the slightly looser shoe may be gripping more to keep the shoe on, leading to overuse of the smaller toe muscles and tendons.
It’s always worth fitting to the larger foot and, where significant size difference exists between feet, looking at footwear solutions that accommodate both sides comfortably. A podiatrist can advise on this if it’s a recurring issue.
Small day-to-day habits, including wearing unsupportive shoes for too long or ignoring early discomfort, can also gradually increase strain on one side more than the other. This is often part of the same pattern behind daily habits that are quietly damaging your feet.
When one side compensates for the other
Sometimes the painful foot isn’t actually the one doing the most work; it’s the one that’s been picking up the slack for a problem on the other side.
If someone has knee pain, hip stiffness, or even chronic lower back pain on one side, they will often shift more weight to the other side to avoid discomfort. The foot on that “good” side ends up loaded beyond its usual share and eventually starts to protest.
This is why a thorough assessment looks at the whole picture rather than just the symptomatic foot. Pain has a habit of showing up somewhere other than its source.
Conditions that tend to affect one side more
Some specific foot and lower limb conditions are more likely to present on one side than both simultaneously, including:
Plantar fasciitis: while it can affect both feet, it very commonly starts on one side, often the dominant or more heavily loaded one
Bunions and hallux limitus: these can develop asymmetrically, particularly if there is a structural difference between the two feet
Achilles tendinopathy: often one-sided, particularly when linked to a difference in calf tightness or loading pattern between legs
Morton’s neuroma: typically affects one foot, most often between the third and fourth toes
Stress fractures: usually occur in one foot at a time and are strongly linked to repetitive loading patterns
In each of these cases, understanding why that particular side is affected, rather than simply treating the symptoms, gives a much better chance of long-term resolution.
Persistent one-sided pain should still be taken seriously, particularly if it is worsening, changing the way you walk, or not settling as expected. In some cases, this raises the question of when foot pain may be a serious condition.
What this means for treatment
One of the most useful things about one-sided pain is that it tells you something. It’s a clue. If both feet were equally painful, it would be harder to identify what’s driving the problem. When one side is worse, it points fairly clearly toward an asymmetry somewhere in the system — structural, mechanical, or habitual — that is worth investigating.
Effective treatment usually involves identifying the underlying asymmetry and addressing it, not just providing relief to the sore foot. That might mean orthotics designed differently for each foot, targeted rehabilitation work on one side of the hip or calf, footwear adjustments, or a combination of approaches.
That might mean custom orthotics designed differently for each foot, targeted rehabilitation work on one side of the hip or calf, footwear adjustments, or a combination of approaches.
The reassuring thing is that one-sided pain is very often very treatable. It just requires looking at the whole picture rather than focusing only on the foot that hurts.
How Hurst Podiatry can help
If you’ve been wondering why one foot keeps giving you grief while the other carries on without complaint, a thorough assessment with one of our podiatrists can help get to the bottom of it.
We look at how you walk, how the load is distributed across both feet and legs, your footwear, your history of injuries, and any structural differences between the two sides. From there, we can put together a plan that addresses what’s actually driving the problem.
Book an appointment with the team at Hurst Podiatry today, because “one foot hurts and the other doesn’t” is a perfectly good reason to come in.
