What causes fungal nail infections?
- How your feet work. Flat feet and other foot function problems can cause repeated small injuries to the nail, which let infection in.
- Footwear. Tight or poorly fitting shoes put pressure on the nails.
- Nail cosmetics. Nail varnish, gel and Shellac can trap moisture and damage the nail surface, making infection more likely.
- Sport. Repeated knocks and pressure in sport can damage the nail.
- Injury. A single injury, such as dropping something on your toe, can damage the nail and allow infection to take hold.
- Sweaty feet (hyperhidrosis). A warm, damp environment is ideal for fungus to grow.
- Diabetes. People with diabetes are around two to three times more likely to get a fungal nail infection.
- Weight and metabolic health. Carrying extra weight, and related conditions such as raised blood sugar, can make fungal infections more likely.
- Your general health. When your immune system is under strain, for example through illness, stress or poor diet, fungal infections can take hold more easily and be harder to clear.
When it isn't fungal: asymmetric gait nail unit syndrome
Not every thick, discoloured nail is a fungal infection. If you walk unevenly, for example because of flat feet, a stiff joint or one leg working harder than the other, your shoe can rub on certain toenails with every step. Over time the nail can lift from the nail bed, thicken and change colour, and look just like a fungal nail.
The difference matters. Antifungal treatment won't help a nail damaged this way, so people can spend months on creams and tablets with no improvement. We check how you walk and what your shoes are doing, and test the nail if needed, so you get the right treatment. Usually that means improving how your foot moves and changing your footwear, so the nail can grow back healthy.
Other conditions, such as psoriasis, can also look like a fungal nail, which is another reason we check before we treat.
How we treat fungal nails
We treat fungal nails in two main ways, working together.
Fenestration. We drill a line of tiny holes into the nail, along the edge where the infection is spreading. It's painless, because the nail itself has no feeling. The holes let treatment reach the infection where it's most active, rather than sitting on the surface.
Laser treatment. We follow fenestration with a course of laser treatment to target the fungus in and under the nail.
Topical treatments. Alongside this, we use topical treatments (applied directly to the nail) at home to keep the infection under control. These include antifungal sprays, silver-based products and natural therapies.
We'll also look at what caused the infection in the first place, such as footwear, foot function or sweating, so it's less likely to come back.
Fungal nails take time to clear, because the healthy nail has to grow out. A big toenail can take 12 to 18 months to grow out completely, so you'll need patience. In our experience, combining these treatments gives the best chance of a clear, healthy nail.
Preventing reinfection
- Keep your feet clean and dry, especially between the toes.
- Change your socks daily, and choose breathable shoes.
- Rotate your shoes, so each pair can dry out.
- Wear flip-flops in communal showers and changing rooms.
- Treat athlete's foot promptly, as it can spread to the nails.
- Give your nails a break from varnish and gels.