Reviewed by Evan Lewis, PhD. Last updated 8 August 2026.
When the side of a toenail hurts and it is not ingrown, the usual causes are a splinter of nail left at the corner after trimming, an irritated skin fold at the base, pressure from a thickened or lifting nail, or an old knock you have forgotten about. All four hurt in the same spot for different reasons.
The short version
- An ingrown nail has something to see: a nail edge in the skin, with redness and swelling on one side.
- Pain with nothing to see is usually a nail splinter left at the corner, a spike you cannot spot from above.
- Pain that comes on in shoes and fades barefoot points to pressure, not an ingrown edge.
- Soak first, look second. Warm water softens the fold enough to see what is under it.
- One-sided toe pain that will not settle over a few weeks gets examined in person, whatever it looks like.
How do you know it is not an ingrown toenail?
An ingrown nail is a mechanical event with a visible cause. StatPearls defines it as the point where "the nail plate grows into the periungual skin, causing inflammation and may lead to infection", and describes the early exam finding as "mild erythema and edema of the lateral nail fold" with "visible penetration of the nail plate into the periungual soft tissue".
So the test is simple. Pull the skin fold gently back from the nail edge with a clean fingertip after a warm soak. If you can see the nail cutting into the flesh, that is an ingrown nail. If the skin is a normal colour and the nail edge is sitting where it should, it is one of the others.
What else causes pain at the side of the toenail?
Five things occupy that few millimetres of foot. Only the first one is an ingrown nail.
| What it is | What it feels like | The giveaway |
|---|---|---|
| Ingrown nail edge | Sharp, constant, worse on pressure | Red, puffy fold with nail visibly in the skin |
| Nail splinter at the corner | Identical to an ingrown nail, stabbing | Nothing visible from above. A spike you feel by running a fingernail along the edge |
| Pressure under a thick or lifting nail | Dull ache, throb at the end of the day | Fine barefoot, sore in shoes. Nail is thickened or has a white gap under it |
| Irritated skin fold at the base | Tender, warm, hurts to touch the cuticle | Swelling is at the base, not the side. Follows picking, biting or cuticle work |
| Something growing under the nail unit | Persistent, one toe, slowly worsening | Months of pain with no visible cause and no response to anything. Needs imaging |
That last row is the reason not to keep guessing forever. The StatPearls differential for an ingrown toenail lists "subungual exostosis, osteochondroma, and tumors of the nail bed or nail folds (benign and malignant)" among conditions that present the same way. Uncommon, and worth a professional eye if weeks pass with no change.
Could it really be a splinter of nail I cannot see?
Yes, and it is the single most common answer to this question in foot care rooms. When a nail is cut in a curve, or torn rather than clipped, a thin spike is left at the far corner under the fold. It keeps growing forward into the flesh.
You cannot see it because the fold covers it. You can often feel it. Soak the foot for ten minutes, dry it, then run the edge of a clean fingernail slowly along the groove between the nail and the skin. A splinter catches.
This is also why the advice is always to cut straight across. A curved cut is what leaves the spike in the first place.
Why does it hurt when there is no redness at all?
Because pain at the side of the toe does not need inflammation. Pressure alone does it. A nail that has thickened, or one that has lifted so there is a gap underneath, transmits every step into the nail bed.
DermNet describes that lifting as onycholysis, "a common nail disorder in which the nail plate has separated from the nailbed typically resulting in a well-defined area of white opaque nail". If there is a pale patch under the sore nail and the shoe test is positive, that is your answer.
The shoe test: does it hurt barefoot on carpet? If not, and it hurts within twenty minutes of putting shoes on, you are dealing with pressure, not an ingrown edge.
What can you do at home tonight?
- Soak in warm water for ten minutes. Plain water is fine. It softens the fold and the nail edge enough to see and feel what is there.
- Dry it properly, then look with good light. Pull the fold gently back. Decide which of the five rows above matches.
- Clip straight across, not curved. Leave the corners where they are. Do not dig down the side.
- Change the shoe. Wide toe box, or an old pair with room. This alone settles a lot of pressure pain within a day or two.
- Keep it clean and dry. Wash daily, dry between the toes, fresh socks.
What not to do
Bathroom surgery is what turns a sore toe into an infected one.
- Do not dig into the corner with scissors or a file to "get it out". You will tear the fold.
- Do not cut a V-notch in the middle of the nail. It does nothing. The nail does not grow that way.
- Do not stuff cotton wool under the edge and leave it for days. Damp packing sits against broken skin.
- Do not keep cutting the sides shorter and shorter. That is what creates the splinter you are now trying to remove.
When should this be looked at in person?
Sooner rather than later if any of these apply:
- You have diabetes, neuropathy, or poor circulation in your feet. Do not self-treat a sore toe at all. Book in.
- There is pus, spreading redness, heat, a red line up the foot, or a fever.
- The pain has been there for weeks with nothing visible to explain it.
- It is one toe, it is getting slowly worse, and nothing you change makes any difference.
- There is a dark streak or a growth of tissue at the nail edge.
A chiropodist or foot care nurse can lift the fold, remove a splinter properly with the right instrument, and have you walking normally the same afternoon. It is a ten minute job for someone with the tools, and a bad idea in a bathroom.
Where a daily routine fits
Most of the causes above come back if the groove between the nail and the fold stays damp and packed with debris. That groove is the hard part of foot care, because it is the one place nothing reaches. Creams sit on top. Brushes paint the surface.
A soak gets into it, which is the whole reason the EZ Clear Nails kit is built around a tray. Two ingredients, iodine and purified water, and no alcohol, so it does not sting a fold that is already sore. It is what over 200 foot care clinics across North America send home with patients after they have dealt with the nail properly in the chair.
If the nail itself is thick and hard to cut, which is often the underlying reason a corner gets left behind, the guide to softening thick toenails is the more useful next read.
Frequently asked questions
Why does the side of my toenail hurt if it is not ingrown?
Most often a thin splinter of nail was left at the corner after trimming and is now pressing into the flesh under the skin fold. Other common causes are pressure from a thickened or lifting nail, an irritated skin fold at the base, or an old knock.
How do I tell an ingrown toenail from something else?
An ingrown nail has visible signs: redness and swelling of the skin fold on one side, with the nail plate visibly pressing into or penetrating the skin. If the fold looks a normal colour after a soak and the nail edge sits where it should, look at the other causes.
Can a toenail hurt with nothing to see?
Yes. Pressure does not need inflammation to hurt. A nail splinter hidden under the fold, or a thickened nail transmitting pressure into the bed, both cause real pain with a completely normal-looking toe from above.
How do I know if there is a nail splinter in the corner?
Soak the foot in warm water for ten minutes, dry it, then run the edge of a clean fingernail slowly along the groove between the nail and the skin. A retained spike catches. Do not dig for it. Have it removed properly if you find one.
Why does my toe only hurt in shoes?
That pattern points to pressure rather than an ingrown edge. A thickened nail or one that has lifted from the bed passes every step into the tissue underneath. Fine barefoot, sore within twenty minutes of putting shoes on, is the classic version.
Should I cut a V shape in my toenail?
No. It is a long-standing myth and it does nothing, because a nail does not grow inward from the middle. Cut straight across, leave the corners alone, and do not cut down the sides.
When should I see a professional about toe pain?
Same week if there is pus, spreading redness, heat, a red line up the foot or a fever, or if you have diabetes, neuropathy or poor circulation. Also if the pain has lasted weeks with nothing visible to explain it, or is slowly getting worse in one toe.
Can a soak help a sore toenail?
A warm soak softens the nail and the skin fold, which makes it easier to see what is going on and more comfortable to trim. It is the first step in almost every at-home routine, and it reaches the groove at the side of the nail that creams and brushes cannot.
Does Betadine help an ingrown toenail?
Betadine is povidone-iodine, an over-the-counter antiseptic, and people reach for it when a nail fold looks angry. It is worth knowing two things before you do. It stains skin, socks and towels a deep brown, and it does nothing about the mechanics. If a nail edge or a retained spike is sitting in the flesh, the edge still has to come out, and that is a job for someone with the right instrument.
What does ingrown toenail removal involve?
For a one-off, a chiropodist or podiatrist lifts the fold, takes out the offending corner or spike, and you walk out the same day. For a nail that keeps digging in, the usual next step is a partial nail avulsion, where a narrow strip down the side is taken away and the matrix behind it is dealt with so that strip does not grow back. Our guide to aftercare once the nail has been done covers the fortnight that follows.
What should I do about a toddler ingrown toenail?
Have it looked at rather than working on the toe yourself. A toddler's nail is short and soft and the skin fold beside it is plump, so a red, tender toe can look exactly like an ingrown nail without the nail being in the skin at all. Warm water, clean socks and shoes with room at the end are the safe things to do while you get an appointment.
Why are my toenails yellow but not fungus?
Plenty of things yellow a nail without a fungus being involved. Dark polish worn back to back, an old knock that bruised the bed, thickening that comes with age, and staining picked up from shoes all do it. We go through the whole list, and what each one looks like up close, in yellow, thick or brittle toenails.
How long does a toenail take to grow out?
Toenails grow at about 1.62mm a month, so a corner cut too far back can take several months to reach the end of the toe again. That slow window is exactly when a spike has time to form, which is why the trimming habit matters far more than any single trim.
For the groove nothing else reaches
The EZ Clear Nails Kit is a soak and spray routine. The tray submerges the toe, so the solution reaches under the free edge and into the folds at the side. Two ingredients, iodine and purified water. No alcohol, no sting, no stain. Used in 200+ foot care clinics across North America, alongside professional care and never instead of it.
Related reading
- Toenail falling off: what to do and how it grows back
- White spots on toenails, and what they do not mean
- How to soften and care for thick toenails at home
- What a chiropodist does, and how it differs from a podiatrist
- At-home aftercare once a professional has trimmed the nail
References
- Dixon M, Bergman R. Ingrown Toenails. In: StatPearls. StatPearls Publishing. NCBI Bookshelf NBK546697
- Ngan V, Kong FW, Muir J. Onycholysis. DermNet, updated December 2020. dermnetnz.org/topics/onycholysis
- Yaemsiri S, Hou N, Slining MM, He K. J Eur Acad Dermatol Venereol. 2010. Toenail growth rate 1.62mm per month. PubMed 19744178
About the author
Reviewed by Evan Lewis, PhD, who specialises in natural and nutritional therapies for the prevention and management of chronic diseases and complications, with a focus on chronic disease, diabetes complications, clinical nutrition, and nerve health.
General information about the toe, not a diagnosis. IodinePure products are cosmetics, used alongside professional foot care and never in place of it.
