When Maria Delgado noticed a dark streak under her big toenail, she assumed it was from dropping her gym bag on her foot. Six months later, that seemingly innocent mark led to a diagnosis that saved ...

For many, running is a passion, an escape, and a fantastic way to stay fit. However, for some, it comes with an unwelcome guest: the black toenail. While not usually serious, it can be painful and ...

Tucked inside their favorite pair of running shoes you’ll find what runners consider both a disgusting side effect of the sport and a badge of honor: bruised, black toenails (if the nail is still even ...