# Thick toenails

> Thick toenails (onychauxis) are common, especially in older people, and are often a normal part of ageing. Other causes include fungal infection, shoe pressure and injury. Gentle filing and regular nail care help first, and a podiatrist can help if the nails are hard to manage.

Guide in [Skin and nails](https://footanklelowerlimb.com.au/learn/topics/skin-and-nails), from Foot Ankle Lower Limb: https://footanklelowerlimb.com.au/learn/nail-thickening
Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod (Podiatrist) on 27 October 2026.
Next review by 27 October 2027.

- **Thickening is common with age,** and it's often not serious.
- **Many things can cause it:** fungal infection, shoe pressure, injury, psoriasis, poor circulation and diabetes.
- **A nail can't be called fungal by looking alone.** Testing nail clippings is what confirms it.
- **Gentle filing and regular nail care come first,** with a podiatrist's help if the nails are too tough to cut.
- **Some nail changes need checking soon,** such as a single dark band or a sore that won't heal.

## What are thick toenails, and how common are they?

Thick toenails (onychauxis) are nails that grow abnormally thick. Over time they may curl and turn white or yellow [1]. They're most often seen in the toenails of older people [2], and toenails are affected more than fingernails [3].

Some thickening is a normal part of ageing. Nails grow more slowly, become brittle, and often thicken and change colour [3]. Nail problems usually aren't caused by anything serious [4]. Thickening can also have other causes, so it helps to know what they are.

It can help to note when the thickening started, which nails are affected, and any colour change, injury or new shoes. Share this with your podiatrist or GP.

## What causes thick toenails?

The commonest causes are fungal infection, ill-fitting shoes, injury, psoriasis (a skin condition that can affect nails), reduced circulation and diabetes. It can also run in families [1]. Long-term ill-fitting footwear and neglected nails are linked with thicker toenails [2].

A fungal infection makes the nail thick, crumbly and discoloured, most often in the big toenail [2]. Toenails get fungal infections much more often than fingernails, partly from shoe pressure and circulation problems [5]. Infection is more likely with diabetes, psoriasis, poor circulation or a weakened immune system [6].

These causes are hard to tell apart by looking. Psoriasis can't easily be told from a fungal infection [2], and injury from shoes can look like one too [6]. Testing nail clippings is what separates them [7].

## How do I find out what's causing it?

A podiatrist or GP will ask about your history, such as psoriasis, injury, nail problems in the family, diabetes, circulation and immune health [7]. They'll also examine your nails. Looking alone can't reliably show the cause, and it's the method most likely to wrongly label a nail as fungal [5].

To check for fungus, nail clippings and debris from under the nail are sent to a laboratory [6]. It's best to do this before any long-term treatment starts [8]. A single negative result doesn't always rule out infection [9].

Testing matters because treating a look-alike condition as a fungal infection can mean the wrong diagnosis, unwanted side effects and the problem getting worse [7].

## What can I do at home first?

Regular cutting and filing reduce the thickness and can ease discomfort and improve how the nail looks [1]. Try gently filing across the thickened part of each nail 2–3 times a week, when the nail is dry, before a bath or shower [10]. Filing downwards, away from your body, once a week can help keep the length and thickness steady. Ask someone to help if you need to [10].

Wearing well-fitting shoes is also sensible, since long-term ill-fitting footwear is linked with thicker toenails [2].

If your nails are too tough to cut or you can't reach them, a podiatrist can help with trimming, shaping and nail care [3][4]. These simple steps are the place to start. Antifungal treatment is for when testing has confirmed a fungal cause [7].

## What helps if that isn't enough?

If testing confirms a fungal infection, antifungal treatment can be added. Medicated nail lacquers and solutions can help, but they clear the infection in relatively few people, and some cause mild skin reactions where they're applied [11].

Antifungal tablets clear the infection better than dummy tablets [12]. They tend to have higher cure rates than treatments applied to the nail, but more significant side effects [13]. If a lacquer or cream hasn't worked, your GP can talk through tablets. A blood test to check your liver is needed first [1], and your other medicines should be reviewed [7].

These treatments are aimed at clearing the fungus. How much they thin the nail isn't clear yet.

For children, tablets are considered only for moderate to severe infection, or long-lasting infection where treatment on the nail hasn't worked. They need regular blood checks [14].

## Will it get better, and can I stop it coming back?

It isn't clear how often thickened nails return to normal or come back. Try not to assume a thick nail will clear or stay clear. Thickening is common with ageing, so it may need ongoing attention [3]. Keeping up regular nail care and wearing well-fitting shoes are sensible habits.

If you have diabetes, poor circulation or a weakened immune system, fungal nail infection is more likely [6]. For people with diabetes, experts recommend preventive foot care alongside nail treatment, with advice on footwear and foot care [15]. Ask your GP or podiatrist about this. See your GP or a podiatrist if a nail changes or the thickening comes back.

## When to see a podiatrist

See your GP soon if you notice a single dark band on one nail, dark colour under the nail, a "bruise" under the nail that doesn't grow out or go away for no known reason, or any area that won't heal, is growing, bleeds or changes colour [2][5][7]. Skin cancer in the nail is rare, but these signs can need a biopsy and referral to a dermatologist [2][7]. In children, a dark band needs checking and long-term follow-up [16].

See your GP if a nail has changed shape or colour or fallen off and you don't know why [4].

See your GP or a podiatrist the same day if:

- the skin around a nail becomes sore, red, swollen and warm [4];
- you have diabetes and notice a wound, sore, blister or colour change on your foot.

For urgent advice when it isn't an emergency, call healthdirect on 1800 022 222 (24 hours a day), or go to a Medicare Urgent Care Clinic.

See a podiatrist if your nails are too tough to cut or you can't reach them [4].

> [!see] If you have diabetes, poor circulation or a weakened immune system
> Problems from nail infection are more common in these groups and can threaten the limb in people with diabetes [12]. See your GP or a podiatrist early about any nail change rather than waiting.

## Common questions

### Is a thick toenail always a fungal infection?

No. Thickening can come from ageing, shoe pressure, injury, psoriasis, poor circulation or diabetes, as well as fungus. These can look alike, so appearance alone can't settle it. A podiatrist or GP can send nail clippings to a laboratory to find out whether fungus is involved.

### Can ill-fitting shoes cause thick nails?

Yes, they can contribute. Long-term use of ill-fitting shoes, and repeated pressure on the toes, is linked with thicker toenails. Shoes with enough room for your toes are a sensible habit. A podiatrist can check your footwear fit and look at your nails.

### Do I need a nail test before antifungal tablets?

Yes, testing first is advised. Other nail conditions can look just like a fungal infection, and treating the wrong problem can cause side effects without helping. Your GP will usually send nail clippings to a laboratory, and arrange a blood test to check your liver before tablets are started.

## Further reading

- [Thick toenails on Clindice](https://clindice.com/nail-thickening)
- [Fungal nail infection: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/001330.htm), MedlinePlus
- [Nail Conditions - NHS Lanarkshire](https://www.nhslanarkshire.scot.nhs.uk/services/podiatry/nail-conditions/), NHS
- [Mycotic Nails: What Is It, Symptoms, Causes & Treatment](https://my.clevelandclinic.org/health/diseases/21712-mycotic-nails), Cleveland Clinic
- [Thick Toenails - Foot Health Facts](https://www.foothealthfacts.org/conditions/thick-toenails?lang=en-US), FootHealthFacts (American College of Foot and Ankle Surgeons)
- [Athlete’s foot and fungal nail infections](https://www.dbth.nhs.uk/wp-content/uploads/2025/12/DP2814-Athletes-foot-Leaflet-08.24.pdf), NHS

## Sources

1. Nail Conditions · NHS Lanarkshire. https://www.nhslanarkshire.scot.nhs.uk/services/podiatry/nail-conditions/
2. ACD A-Z of Skin - Nails · ACD. https://www.dermcoll.edu.au/atoz/nails/
3. Nails - fingernail and toenail problems · Better Health Channel · 2010. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/nails-fingernail-and-toenail-problems
4. Nail problems · NHS. https://www.nhs.uk/symptoms/nail-problems/
5. The Diagnosis and Treatment of Nail Disorders · Wollina U, Nenoff P, Haroske G et al. · Deutsches Arzteblatt International · 2016. https://doi.org/10.3238/arztebl.2016.0509
6. Fungal Nail Infection: Causes, Symptoms, and Treatment · NHS. https://best.barnsleyccg.nhs.uk/media/pzbbc30i/fungal_nail_infection_tinea_unguium-may-2023.pdf
7. Optimal diagnosis and management of common nail disorders · Lee DK, Lipner SR · Annals of Medicine · 2022. https://doi.org/10.1080/07853890.2022.2044511
8. Fungal skin and nail infections: Diagnosis and laboratory investigation Quick reference guide for primary care: Summary table · assets.publishing.service.gov.uk. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/619769/Fungal_skin_and_nail_infections_guidance_summary_table.pdf
9. Literature review. Onychomycosis · Hay R · Journal of the European Academy of Dermatology and Venereology · 2005. https://doi.org/10.1111/j.1468-3083.2005.01288.x
10. Information on Thickened Toenails · NHS. https://www.nhsborders.scot.nhs.uk/media/904755/Thickened-toenails.pdf
11. Topical and device-based treatments for fungal infections of the toenails · Foley K, Gupta AK, Versteeg S et al. · The Cochrane Database of Systematic Reviews · 2020. https://doi.org/10.1002/14651858.cd012093.pub2
12. Oral antifungal medication for toenail onychomycosis · Kreijkamp-Kaspers S, Hawke K, Guo L et al. · The Cochrane Database of Systematic Reviews · 2017. https://doi.org/10.1002/14651858.cd010031.pub2
13. Unveiling onychomycosis: Pathogenesis, diagnosis, and innovative treatment strategies · Shah AA, Mirza R, Sattar A et al. · Microbial Pathogenesis · 2025. https://doi.org/10.1016/j.micpath.2024.107111
14. Pediatric dermatophyte onychomycosis: a review · Gupta AK, Taylor D · International Journal of Dermatology · 2025. https://doi.org/10.1111/ijd.17495
15. Patients at risk of onychomycosis--risk factor identification and active prevention · Tosti A, Hay R, Arenas-Guzmán R · Journal of the European Academy of Dermatology and Venereology · 2005. https://doi.org/10.1111/j.1468-3083.2005.01282.x
16. Melanoma-like features in pediatric longitudinal melanonychia: A systematic review and meta-analysis · Tsai SY, Hamilton CE, Mologousis MA et al. · Pediatric Dermatology · 2024. https://doi.org/10.1111/pde.15597

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This page is general information, not a diagnosis or a treatment plan for you. For advice about your own feet or legs, see a podiatrist or your doctor. In an emergency, call 000.