What Causes Ingrown Toenails and How to Prevent Them
| The main answer | What causes ingrown toenails? The nail edge grows into the skin — usually from cutting nails too short or curved, tight shoes, naturally curved nails or a toe injury. |
| The big myth | Cutting a V in the nail does nothing. Nails grow forward, not inward, so a central notch cannot stop the sides digging in. |
| What prevents them | Trim straight across, do not cut too short, wear roomy shoes, keep feet clean and dry, and keep the skin soft. |
Few small problems cause as much day-to-day misery as an ingrown toenail: that hot, throbbing corner that makes putting on a shoe an event. If you have been searching what causes ingrown toenails, you are almost certainly hoping for two things — to understand why it keeps happening, and to stop it happening again. The encouraging news is that the vast majority of ingrown toenails come from a small set of everyday, fixable causes, and a few simple changes to how you trim and shoe your feet prevent most of them.
This guide explains exactly what an ingrown toenail is, the everyday causes behind it, the trimming myths that make things worse, the daily habits that genuinely prevent them, and the clear signs that it is time to let a professional take over.
What an ingrown toenail actually is
An ingrown toenail (the medical term is onychocryptosis) happens when the side or corner of a toenail grows into the soft skin of the nail fold beside it, rather than gliding out over the top. The skin responds the way it would to any splinter: it becomes red, swollen, tender and sometimes weepy, and if bacteria get in it can become infected. The big toe is by far the most commonly affected because it takes the most pressure from shoes and the ground. Understanding that the problem is a sharp edge of nail pressing into skin — not the nail “growing wrong” from deep inside — is the key to preventing it, because almost every prevention step is about keeping that edge smooth and away from the skin.
The everyday causes of ingrown toenails
Most ingrown toenails trace back to one or more of these ordinary causes:
- ✓ Cutting nails too short. The skin bunches over the corner and the nail then grows into it — the number-one cause.
- ✓ Rounding the corners. Curving the cut down the sides leaves a spike that digs in as it grows.
- ✓ Tight, narrow or short shoes. Pressure crowds the toes and pushes the nail edge into the skin.
- ✓ Naturally curved or fan-shaped nails. Some people simply have nails that curl into the fold — often it runs in families.
- ✓ Injury. Stubbing the toe or dropping something on it can change how the nail grows.
- ✓ Sweaty feet. Constantly damp skin is softer and easier for a nail edge to pierce.
That last point ties ingrown toenails to the wider issue of keeping feet dry — if yours run hot and moist inside shoes, the habits in why feet sweat and smell help here too.
The trimming myths that make things worse
Ingrown toenails come wrapped in bad advice, and two myths do real harm. The first is cutting a V or notch in the centre of the nail to “draw the sides in.” Nails grow forward from the base, not sideways from the middle, so a central notch achieves precisely nothing — it just weakens the nail. The second is digging down the side to hook out the ingrown corner yourself. This almost always tears the skin, leaves a sharper spike behind and opens the door to infection. The correct approach is dull by comparison but it works: trim straight across, leave the nail level with or just beyond the end of the toe, and gently file any sharp corner smooth rather than cutting into it.
Keep the skin around your nails soft and cared for
Supple, well-conditioned skin around the nail is easier to keep clear of a growing nail edge, and daily foot care is where prevention lives. TerraCalm is a once-daily topical mineral clay complex with clove, tea tree and oregano plus vitamin E, aloe and shea butter, made for everyday foot and nail conditioning. It is a cosmetic care product, not a treatment for ingrown toenails — but keeping feet clean, soft and cared for is part of good foot hygiene. Backed by a 60-day guarantee.
Daily habits that prevent ingrown toenails
Prevention is genuinely effective here, and it comes down to how you cut, what you wear and keeping feet healthy:
- ✓ Trim straight across. Use clean, sharp clippers and cut in a straight line, not a curve.
- ✓ Do not cut too short. Leave the nail level with the end of the toe so no skin can bunch over the corner.
- ✓ File sharp corners. Smooth any pointed edge with a file instead of cutting into it.
- ✓ Give toes room. Choose shoes and socks with a wide toe box; avoid tight, pointed styles for long days.
- ✓ Keep feet clean and dry. Wash daily, dry between the toes, and change damp socks promptly.
- ✓ Soak and soften. A warm soak makes nails easier to trim cleanly and keeps the nail fold supple.
- ✓ Condition the skin. Keeping the skin around the nail soft and healthy supports the whole routine.
Where conditioning care fits
Preventing ingrown toenails is mostly about trimming technique and footwear, with healthy, supple skin around the nail as a supporting cast. Botanical oils and butters such as vitamin E, aloe, shea, jojoba and sweet almond keep the nail fold soft, while clove, tea tree and oregano are traditionally valued in foot care, and mineral clays like bentonite and kaolin help keep the surface clean and balanced. A once-daily routine with TerraCalm makes that everyday foot care effortless — though it is care and hygiene, not a treatment. For the broader picture, read how to keep your nails healthy and strong.
When an ingrown toenail needs a professional
Do not tough it out if things are getting worse. See a doctor or podiatrist if the toe is very painful, the skin is red, swollen, warm or oozing pus (signs of infection), if you keep getting ingrown toenails in the same spot, or if the corner is already deeply embedded. A podiatrist can safely lift or remove the offending edge, and for recurring cases can perform a small, straightforward procedure to stop it coming back. This is especially important — and should not be delayed — if you have diabetes, nerve problems in the feet or poor circulation, because foot infections can escalate quickly.
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What the clinical literature says about ingrown toenails
An ingrown toenail is a mechanical problem before it is an infection: the nail edge presses into the fold, the skin reacts, and the reaction narrows the space further. A 2026 clinical review in the Journal of the American Academy of Dermatology places ingrowing among the mechanical and structural nail disorders and describes conservative management — correct trimming, footwear, packing the edge — as the first line for early cases Ricardo et al., 2026.
When conservative care fails, the question becomes which procedure. A comparative analysis in the Journal of the American Podiatric Medical Association weighed the surgical options for ingrown toenails against recurrence and recovery Yurteri et al., 2025 — a decision for a clinician, not a home remedy. A broader review of common nail disorders in Annals of Medicine is the reference worth reading if you are not certain the problem is ingrowing at all Lee & Lipner, 2022.
Ingrowing and thickening frequently travel together, because both are driven by pressure from footwear and by the shape a nail takes on over decades. If the nail giving you trouble is also hard to cut straight, the reasons toenails become thick and hard explain a good deal of why it keeps catching.
Frequently asked questions
What causes ingrown toenails?
An ingrown toenail happens when the edge of the nail grows into the skin beside it. The most common everyday causes are cutting the nails too short or curving them down at the corners, tight or narrow shoes that press the toe, naturally curved or fan-shaped nails, an injury such as stubbing the toe, and sometimes sweaty feet that soften the skin. The big toe is affected most often.
How do you prevent ingrown toenails?
Cut toenails straight across rather than rounding the corners, and do not cut them too short. Wear shoes and socks with enough room in the toe box, keep feet clean and dry, and file any sharp corners smooth. Soaking the feet and keeping the surrounding skin soft makes the nail edge easier to lift gently away from the skin. People with curved nails may need a podiatrist’s help.
Should you cut a V in an ingrown toenail?
No. Cutting a V or notch in the middle of the nail is a myth and does not stop the sides growing into the skin — nails grow forward, not inward, so a central notch does nothing. Digging down the sides to remove the ingrown part yourself often makes it worse and risks infection. Trim straight across and see a podiatrist if the corner is already embedded.
Are ingrown toenails caused by tight shoes?
Tight, narrow or short shoes are a major contributor. They press the sides of the nail into the skin and crowd the toes, which encourages the edge to dig in, especially in people who are on their feet a lot or play sport. Roomy footwear with a wide toe box is one of the most effective prevention steps.
Can I fix an ingrown toenail at home?
A very mild, early ingrown toenail with no infection can sometimes settle with warm soaks, careful straight-across trimming, gently easing the skin away and wearing roomy shoes. But if it is painful, red, swollen or oozing, or if it keeps recurring, do not keep digging at it — see a professional. People with diabetes or poor circulation should have any ingrown toenail assessed rather than self-treating.
Does TerraCalm treat ingrown toenails?
No. TerraCalm is a cosmetic topical mineral clay complex for everyday foot and nail care. It does not treat, cure or prevent ingrown toenails or any medical condition. Keeping the nail and surrounding skin soft and cared for is part of good general foot hygiene, but an established or infected ingrown toenail needs proper medical attention.
References
- Yurteri A, et al. “A Comparative Analysis of Surgical Interventions for Ingrown Toenails” Journal of the American Podiatric Medical Association, 2025. PMID 41468162
- Ricardo JW, et al. “Evaluation and management of mechanical and structural nail disorders: A clinical review” Journal of the American Academy of Dermatology, 2026. PMID 41242632
- Lee DK, Lipner SR. “Optimal diagnosis and management of common nail disorders” Annals of Medicine, 2022. PMID 35238267
- Mayo Clinic. “Ingrown toenails – symptoms and causes.” mayoclinic.org
- American Academy of Dermatology. “How to trim your nails.” aad.org
- NHS. “Ingrown toenail.” nhs.uk
- MedlinePlus (U.S. National Library of Medicine). “Ingrown toenail.” medlineplus.gov
The TerraCalm Research Team is an independent group that writes plain-language, evidence-aware guides on everyday foot, skin and nail care. We read primary dermatology and public-health sources, describe ingredients in terms of their traditional and general use, and are careful to separate cosmetic care from medical treatment. Our articles are reviewed for accuracy before publishing and are intended for general education — not as a diagnosis or a substitute for your own clinician’s advice.
† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. This article is for general information only and is not medical advice; consult a qualified professional about your individual situation.