nail fungus and onychomycosis: prevention, symptoms, and treatment

also known as onychomycosis, nail fungus is a common contagious infection that affects toenails and fingernails.

by dave yasvinski

published nov 23, 2022

last updated apr 06, 2023

3 minute read

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3 minute read

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nail fungus and onychomycosis: prevention, symptoms, and treatment

fungal infections typically begin as a white or yellow spot underneath the surface of a fingernail or toenail. getty

nail fungus, also known as onychomycosis, is a progressive fungal infection that affects the toenails and, less commonly, the fingernails. these infections, which are very common and contagious, occur when fungi manage to get between the toenail and nail bed (the area directly beneath the nail), usually through a crack or cut in the skin. an untreated nail fungus, according to the canadian nail fungus resource, will not go away on its own and can worsen to the point where it becomes painful to walk. onychomycosis infections typically begin as a white or yellow spot underneath the surface of a fingernail or toenail but worsen as the infection deepens, with nails becoming thicker, discoloured and crumbly at the edges. nail fungus, which can result from direct contact with an infected person or surface, are more common in warm, moist places, such as public changerooms, showers or swimming pools. while anyone is susceptible to onychomycosis, the condition becomes more common with age, possibly due to decreased blood circulation and weakened immune systems.

symptoms of nail fungus

if you have a fungal infection of your fingernails or toenails, you may notice some of the following symptoms:

nails that are abnormal in shape or discoloured
nails that are brittle or appear to be crumbling
thickening of the affected nails
debris under the nails
nails that emit a slightly foul-smelling odour

diagnosing onychomycosis

to diagnose nail fungus, doctors will typically take samples or scrapings from beneath a nail to identify the issue, according to the toronto dermatology centre. these samples are sent to a laboratory that can culture and identify the fungus behind the infection.

nail fungus treatment options

treating nail fungus usually involves taking an oral antifungal drug, such as terbinafine or itraconazole. these drugs, which are generally avoided for pregnant patients or people with a history of liver problems, can clear infections more quickly than topical medications that struggle to penetrate the nail. the course of oral drugs can take up to six weeks but it can take months longer for a new, uninfected nail to replace the old one. antifungal creams or nail polishes may be prescribed in combination with oral medication. even when treatment proves successful, repeat infections are common. in extreme cases, where an infection does not respond to treatment, a doctor may recommend surgery to permanently remove a nail.

preventing nail fungus

the best way to avoid a fungal infection, according to the canadian dermatology association, is to closely observe the following advice:

keep skin clean and dry
do not share nail clippers, files or similar tools
use antifungal sprays or powders every day
avoid going barefoot in public places
trim nails straight across
give feet time to breathe by removing shoes and socks regularly

onychomycosis prevalence

estimates of onychomycosis rates in canada vary, as not everyone with an infection seeks treatment. one study estimates that around seven per cent of the general population is affected but other estimates put the number as high as 20 per cent. prevalence increases with age and it is believed that around 50 per cent of people over the age of 70 have onychomycosis, with men in that age group 2.1 times more likely to experience nail fungus than women.

support for nail fungus

for more information about onychomycosis, visit the canadian skin patient alliance and the canadian nail fungus resource can provide more information about onychomycosis and find useful advice on nail fungus treatment and how to prevent a repeat occurrence.

dave yasvinski is a writer with healthing.

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dave yasvinski

nail fungus and onychomycosis: prevention, symptoms, and treatment