“The causes of thickened and yellow toenails are as follows.
It is most likely to be caused by a fungal infection called ‘grey nails’ or malnutrition. When the fungus invades the toenail, it can easily become infected if the nail is in an environment that is conducive to fungal growth, such as confinement, humidity or high temperatures.
The fungus invades the surrounding skin and nail plate, affecting the growth of the nail and promoting the accumulation of keratinous material around it, causing the nail to thicken and become cloudy; in addition, when the toenail is malnourished, the surface of the nail loses its lustre and becomes yellow and uneven.