Nail fungus is usually caused by exposure to moist environments such as shower floors and swimming pools. To prevent and treat, look for oils and balms with the keywords “anti-inflammatory” and “anti-microbial”. Neem is a great ingredient, as it has both of these properties and is also an anti-fungal. There are lots of great neem oil products on the market – look for organic whenever possible, please. And as always consult your doctor about treating nail fungus. …And do not send us pictures – thanks in advance.