Answer:
Fungal infection.
Step-by-step explanation:
This type of infection is caused by many different fungal organism. The most famous condition that is caused by fungi is dermatophyte. This type of infection is usually caused when a person is suffering from athlete's foot ( fungus ), and it can easily spread from one infected nails, to either all of them, or maybe 2-3 more. Fungal nail infection is usually triggered by yeasts and molds. The result is -- thick and discolored nails which are more likely to break.