Why are my toenails unsightly?

Thick, discoloured or oddly shaped toenails are common, and they often become more noticeable in sandal season. There are several possible causes, and they can look quite alike, so getting the right diagnosis matters before you spend time and money on treatment. Here are the most common reasons toenails change, and what can help.

Is it a fungal infection?

A fungal nail infection (onychomycosis) is one of the most common causes of unsightly toenails, especially in older people [1]. It often starts when a fungal skin infection such as tinea spreads to the nail [1].

Signs include [1]:

• a yellow or brown nail, or white spots on the nail
• a thickened nail that crumbles when you cut it
• the nail lifting away from the skin underneath
• pain or a bad smell under the nail.

You're more likely to get it if you have sweaty feet, wear closed shoes for long periods, have diabetes or a weakened immune system, or have a skin condition such as psoriasis [1].

Does treatment work? Fungal nails are hard to clear. Most people need antifungal tablets from their doctor, taken for 3–6 months or longer [1]. Antifungal creams and paints don't usually work well on toenails on their own [1]. Laser can help, especially combined with an antifungal paint, although results vary with the laser used (more about laser). The infection can also come back after treatment [1]. A podiatrist can thin and trim thick nails so they're more comfortable and look tidier while you decide on treatment.

Could it be an injury?

Injury is another common cause. A single knock, such as stubbing your toe, can cause bleeding under the nail, which turns it purple or black [2]. Repeated pressure from tight shoes, or from running and kicking sports, can also bruise, thicken or lift the nail. Damage to the area where the nail grows can sometimes cause permanent changes to its shape.

Is it an ingrown or curved nail?

An ingrown toenail is when the side of the nail curls down and grows into the skin [3]. It can be painful, red and swollen, and it can become infected [3]. Causes include tight shoes or socks, cutting nails too short or not straight across, injury, sweaty feet, and nails that are naturally curved [3].

Mild ingrown nails can often be managed without surgery, for example with better-fitting shoes and a nail brace [4]. A nail brace is a thin strip fixed to the surface of the nail that gently reshapes it as it grows. We use a brace system called Onyfix. If an ingrown nail keeps coming back, part of the nail can be removed under local anaesthetic [3].

Could it be something else?

Other causes of nail changes include:

• Ageing. Nails often develop lengthwise ridges as you get older [2].
• Skin conditions. Psoriasis and eczema can cause small pits in the nail, and psoriasis can make the nail lift [2].
• Illness. A serious illness or some medical treatments can cause a groove across all the nails, called a Beau line, as nail growth stops for a while [2].
• Bacterial infection. A green nail can be caused by an infection with bacteria called Pseudomonas, or by a yeast called Candida [2].
• A bony growth under the nail. A subungual exostosis is a small, harmless bony growth under the nail, most often on the big toe. It can lift the nail and be painful, and can look like other nail problems. An x-ray confirms it, and it's usually treated with minor surgery [5].

When to see a podiatrist

See a podiatrist or GP if:

• your nail is painful, red, swollen or oozing pus [3]
• you have diabetes, poor circulation or a weakened immune system [1][3]
• the change is spreading to other nails [1]
• you're not sure what's causing it.

See a doctor promptly if you notice a new dark streak in a nail that you didn't injure, especially if it's widening or changing, darkening of the skin next to the nail, or a lump under the nail. These can be signs of melanoma under the nail [6].

At Foot Ankle Lower Limb, we can work out what's affecting your nails, treat ingrown nails, and help keep thick or damaged nails comfortable. To get your nails checked, book an appointment.

References

1. Healthdirect Australia (2024). Toenail infection. https://www.healthdirect.gov.au/toenail-infection
2. Oakley A (2023). Nail terminology. DermNet. https://dermnetnz.org/topics/nail-terminology
3. Healthdirect Australia (2025). Ingrown toenails. https://www.healthdirect.gov.au/ingrown-toenails
4. Nielsen JJS, Grim R, Mortensen JF, et al. (2024). Ingrown toenail. Ugeskrift for Læger, 186(39), V01240046. https://doi.org/10.61409/v01240046
5. Wong K (2009). Subungual exostosis. DermNet. https://dermnetnz.org/topics/subungual-exostosis
6. American Academy of Dermatology (2021). How to check your nails for melanoma. https://www.aad.org/public/diseases/skin-cancer/types/common/melanoma/nail-melanoma

Reviewed by Andrew Schox, Podiatrist, BSc(Hons) PGradDipPod MPod. Last reviewed October 2026.