With summer around the corner in the UK, the warmer conditions and greater opportunities to be barefoot (around swimming pools for example) create an ideal breeding ground for fungi. Fungal nail infections are one of the most common nail conditions in the UK, yet many people delay treatment until the infection is well established.1 The earlier you act, the more straightforward treatment tends to be. Here are five warning signs that are worth taking seriously.
1. Yellow, White or Brown Discolouration
Discolouration is usually the first visible change, and it often begins as a small white, yellow or brownish patch near the tip of the nail.1 This happens because the fungus, typically a group called dermatophytes, begins to break down the nail plate from underneath. As the infection spreads toward the nail base, the discoloured area gradually grows to cover more of the nail surface.
It can be easy to dismiss early discolouration as a bruise, residual nail polish staining, or general wear. Unlike a bruise, however, fungal discolouration does not grow out toward the tip as the nail lengthens. If a patch persists or continues to spread over several weeks, that pattern is a reliable indicator of infection rather than superficial staining.
Acting at this stage is worthwhile because the infection has not yet progressed to the nail base, where treatment becomes more difficult. Products such as Curanail and Loceryl contain amorolfine 5% nail lacquer and are available without a prescription from a UK pharmacy.2 Consistent weekly application at this early stage gives you the best chance of clearing the infection before it takes hold further.
2. The Nail Becoming Unusually Thick
As the infection progresses, the nail often starts to thicken noticeably. This happens because the nail plate responds to fungal invasion by producing excess keratin, a process called subungual hyperkeratosis. The result is a nail that is harder, denser, and more difficult to trim than usual, and it may also begin to change shape.3
Significant thickening can put pressure on the toe inside a shoe, causing discomfort when walking or wearing close-fitting footwear. Some people find the affected nail becomes so hard to cut that it requires a pharmacist or podiatrist to manage it safely. If you notice a toenail becoming noticeably thicker or misshapen, this is a sign the infection has moved beyond the earliest stage.
Treatment should begin without delay at this point. An amorolfine nail lacquer remains the appropriate first-line option, though it will take consistent use over several months before improvement becomes visible.2 New healthy nail growing from the base is the sign that treatment is working, so patience is part of the process.
3. Brittleness and Crumbling Edges
A healthy nail bends slightly under pressure without breaking. A fungally infected nail often becomes brittle, so pieces may break off or crumble at the edges when you try to file or cut it. You might also notice a powdery or chalky residue collecting beneath or around the nail.4
In more advanced cases, a faint musty smell when trimming the nail can be a further indicator. The debris that builds up under an infected nail is a combination of keratin fragments and fungal material. At this stage, the structural integrity of the nail has been significantly compromised, and the infection is unlikely to resolve without treatment.
It is also worth being aware that crumbling nail tissue can create small breaks in the skin nearby, which slightly increases the risk of a secondary bacterial infection entering through the damaged area. If the skin around the nail becomes red or swollen, or you notice any discharge, speak to a pharmacist or your GP rather than continuing to self-manage.
4. The Nail Lifting Away from the Nail Bed
When the nail begins to separate from the skin underneath, this is called onycholysis. You may notice a white or yellowish gap appearing between the nail and the nail bed, starting at the tip and working inward.3 The nail may appear partially detached and can snag on socks or catch on clothing, which can be uncomfortable.
This sign indicates that the infection has reached a more advanced stage. The gap created by onycholysis also traps moisture and debris underneath the nail, creating conditions that make the infection easier to sustain and harder to shift. It can also allow additional organisms to enter, complicating the picture.
If the skin around the lifting nail becomes red, swollen or painful, or if there is any fluid or pus present, you should speak to your GP or pharmacist promptly rather than waiting.4 These signs can indicate a secondary bacterial infection that requires different treatment to the antifungal lacquer. Do not try to force the nail back into contact with the nail bed, as this can cause further damage to the underlying tissue.
5. Scaly or Itchy Skin Around the Nail
Fungal nail infections are often linked to athlete's foot, which is caused by the same group of dermatophyte fungi.1 If you notice dry, flaky or itchy skin between your toes or around the base of the affected nail, this may indicate the infection is present on the skin as well as the nail. The two conditions frequently occur together and can sustain each other if only one is treated.
Treating athlete's foot promptly is important because if it is left unaddressed, it can spread to the nails. Equally, a nail infection that has been successfully treated can reinfect the surrounding skin, so tackling both at the same time is the more effective approach.2 Antifungal creams for athlete's foot are available over the counter and should be used alongside any nail lacquer treatment if both areas are affected.
A pharmacist can advise on the appropriate products and, if needed, help you understand whether what you are seeing is more consistent with athlete's foot, a fungal nail infection, or both. Getting a clear assessment at this stage can save time and ensure you are treating the right condition in the right way.
Frequently Asked Questions
Can a fungal nail infection go away on its own?
It is unlikely. NHS guidance confirms that fungal nail infections rarely resolve without treatment.1 While mild cases may not cause significant discomfort, the infection typically continues to spread if left untreated, and the nail can become progressively more discoloured, thickened and damaged over time. Starting treatment early, when only part of the nail is affected, gives the best chance of a good outcome.
What is the best treatment for a fungal nail infection in the UK?
For most cases, first-line treatment is an antifungal nail lacquer containing amorolfine 5%, available over the counter without a prescription. Branded options include Curanail and Loceryl. The lacquer is applied directly to the affected nail once or twice weekly, and treatment typically continues for nine to twelve months for toenails until healthy nail has fully regrown from the base.2 If pharmacy treatment does not improve the nail after consistent use, a GP can prescribe antifungal tablets.
How do I know if it is a fungal infection or something else?
Fungal nail infections can look similar to other nail conditions, including nail psoriasis or damage from trauma. The distinguishing features of a fungal infection are discolouration that starts at the nail tip and spreads toward the base, progressive thickening, and crumbling.3 If you are unsure, a pharmacist can help assess your nail. A GP can take a nail clipping for laboratory testing to confirm the diagnosis if the presentation is unclear or if treatment has not worked.
When should I see a GP about a nail infection?
You should see a GP if pharmacy treatment has not improved the nail after three months of consistent use, if the infection appears to be affecting the base of the nail, or if you have a condition that affects your immune system or circulation, such as diabetes.1 Seek prompt advice if the skin around the nail becomes hot, swollen, painful or produces fluid, as this can indicate a bacterial infection that needs different treatment.4
References
- NHS. Fungal nail infection. Available at: nhs.uk/conditions/fungal-nail-infection
- Guy's and St Thomas' NHS Foundation Trust. Fungal nail infections. Available at: guysandstthomas.nhs.uk
- British Association of Dermatologists. Fungal nail infections. Available at: bad.org.uk/pils/fungal-nail-infections
- NICE Clinical Knowledge Summary. Fungal nail infection. Last revised August 2023. Available at: cks.nice.org.uk/topics/fungal-nail-infection
This article is intended for informational purposes only and does not replace professional medical advice. Always read the patient information leaflet supplied with your medication and speak to a healthcare professional if you have specific concerns.