Occuring when microscopic fungi enter through a break in the nail, a fungal infection can make your nails thick, discolored and brittle.

多由真菌通过趾甲缝隙进入趾甲而感染，引起趾甲增厚，变色和变脆。

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The National Institutes of Health, unfortunately, describes fungal nail in less-than-clear terms: Fungal nail infection is an infection of the nails by a fungus.

CNN: For pedicures, be careful where you step