Usually, your healthcare provider must confirm your diagnosis using laboratory tests before prescribing antifungal treatment. To confirm the diagnosis, the healthcare provider may collect a nail sample to look at under a microscope or send it to a laboratory for analysis. The healthcare provider will examine your nails and may take some nail clippings or scrape off any debris under the nail. These samples are sent to a laboratory to identify the cause of the symptoms.
To find out if a patient has nail fungus, a dermatologist examines the nails and nearby skin. It's important to examine the skin because the fungus can spread. You may already have a skin infection caused by a fungus, such as athlete's foot. This test is used to detect and diagnose nail infections using a PAS stain.