Fungal nail infection - Causes 

Causes of a fungal nail infection 

The most common causes of fungal nail infections are a fungal skin infection or damage to the nail or skin.

Athlete's foot

A fungal infection in the toenail is often caused by a fungal skin infection such as athlete's foot. About a third of people with athlete's foot also develop a nail infection. Athlete's foot usually affects the skin between your toes, causing it to become red, flaky and itchy.

Fungi grow and thrive easily in warm, damp environments, so an infection is more likely to occur after wearing trainers for long periods or if you often have hot, sweaty feet.

Other causes

Fingernail infections are most often caused by a yeast called candida, which causes infections such as vaginal thrush.

You're more likely to develop a fingernail infection if your job involves a lot of handwashing or your hands are in water for long periods of time. This is because the skin at the base of your nail can become damaged and is more likely to become infected.

Your risk of developing a fungal nail infection is also increased if you have certain health conditions or health issues, such as:

Other factors that can increase the risk of nail infections include:

  • using artificial (cosmetic) nails
  • nail damage
  • constant nail biting
  • living in a warm and humid climate
  • smoking

Nail infections are more likely to occur with increasing age. Sometimes there's no obvious cause for an infection.

Page last reviewed: 10/01/2014

Next review due: 10/01/2016


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The 3 comments posted are personal views. Any information they give has not been checked and may not be accurate.

margarethe said on 13 October 2014

I agree with Gillyinnes below, I tried the liquids etc for nails but they didn't help. I used a tea tree cream which I rubbed in daily. Also I disinfected all my socks which I think helped a lot.

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Gillyinnes said on 09 October 2014


I have discolouration of both sides of big toes I think came from some shoes I wore - anyway - its a fungal nail infection. I looked at various treatments like the tablets, the liquid you put on after filing your nails down etc ... but decided to go natural ... I purchased organic:
1. May Cheng essential oil (Anti fungal)
2. Tea Tree Oil (Anti fungal, anti bacterial, antiseptic)
3. Lavender Oil (Anti toxin - draws out toxins, anti bacterial)
4. Oregano Oil (Anti fungal, anti bacterial, anti microbal)

In a small dropper bottle i put 10 drops of each of the oil then topped the bottle up with any carrier oil (almond / jojoba / even olive oil or castor oil is ok)

After 1 week the dark yellow has faded to pale yellow with me bathing my feet and drying them thoroughly each night and applying the mixture 2 timer per day, rubbing it on top of and behind the nail and down the sides and letting it soak in. I put clean socks on each day and bought cheap disposable slipper that i change ever two days :-D

I am also going to try what other people on here have suggested ... the apple cider vinegar and water foot soak .... and vicks vapour rub ... ill repost result next month.

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SpiffyRicky523 said on 15 February 2013

I like the information presented here. It gives a great outlook on how toenail fungus is contracted and what can be done to help avoid contracting it. There is another place I have read about the causes which are not listed in this article; The main one I believe is watch out when you go to nail salons. A lot of times, they don't properly sterilize the instruments.

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