Fungal Nail Infections

Updated: April 2021


Fungal nail infections cause the nail to become thick or discoloured. If left untreated the infection may spread over the whole nail or to other nails. The nail change may vary greatly depending on the type of fungus and location of the infection (under or on top of the nail).


Signs or symptoms you may experience:

  • The nail may have a yellow colour under the nail or a white colour on top.  

  • Usually there is no pain from a fungal nail infection.

  • The nail may be thickened compared to other nails.

  • There may be a buildup of skin under the nail.

  • The nail may be loose (not attached to the skin under the nail).

If it's not a fungal nail infection, what else might it be:

Not all discoloured nails or thick nails are fungal. A pathology test may be required to confirm a fungal nail infection. 

  • Direct trauma (drop something heavy on toe) causing bleeding under the nail, usually a brown-black colour.  

  • Indirect trauma (minor knocking or pressure on nail from inside of shoe over many years) may cause the nail to become thickened with a yellowish colour.  

  • Separation of the nail from the skin under the nail will cause a whitish colour.

  • Psoriasis may cause nail changes that look like a fungal nail infection.

Treatment options:

The aim of treatment is to resolve the infection, improve the appearance of the nail and address any related issues.  Usually a combination of treatments will be required. While the aim of treatment is to resolve symptoms, some individuals may have no benefit or increased symptoms from some treatments. Cease these treatments and contact Inform Podiatry.

There are four main treatment options: 

  1. Watch and wait, if the nail grows faster than the fungus then the nail will 'push' the fungal infection out (less than 25% success rate).

  2. 12 to 48 week course of topical treatment, usually a liquid anti-fungal to paint on the nail (25-50% success rate).

  3. 12 to 24 week course of prescribed anti-fungal tablets from a GP (50-75% success rate).

  4. Laser treatment, 4 to 6 sessions (25-75% success rate).


The Therapeutic Guidelines recommends a pathology test should be done before treatment to confirm a fungal infection. They also recommend prescribed anti-fungal tablets as the preferred treatment option if more than one nail involved, more than 50% of the nail is infected or topical treatment was unsuccessful.

All treatment options are more successful with the following additional treatments:

  • Discoloured nail is cut back to the normal nail and thick nails are thinned down.

  • Treat any fungal skin infection on the foot (usually between the toes or on the sole of the foot) with a topical anti-fungal cream.

  • Wear socks and stockings with footwear and wash them after each wear.

  • Reduce risk of fungal reinfection from footwear with an ultraviolet shoe sanitizer treatment. Inform Podiatry uses ShoeZap.


Inform Podiatry provides these webpages for general advice.  Please book an appointment at Inform Podiatry for individual assessment and treatment of your foot or lower leg condition.

Key words:

Fungal nail infection | Onychomycosis | Tinea unguium