Proliferous, thready and mould fungal infections are differentiated. The guest has to be sent to a doctor. However, the thickened yellowy-coloured nail funguses can be treated (thready fungus is the most general type of toenail funguses). After shortening it with nail clippers we should remove the debris from under the nail-plate with a medium-sized grafting-knife then narrow the thickened nail-plate with a nail-scraper. Finally we have to apply fungicide on the nail. The guest has to be sent to a doctor. Shoes have to be disinfected with cotton-wool soaked in formalin.