If you're a runner, you know that black toenails are common—but that doesn't mean you have to put up with them. Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a ...

Both a bane to runners and—in some strange way—a badge of honor, the black toenail, or subungual hematoma, is actually blood collecting underneath your nail. It can occur from acute or chronic injury, ...

Sarah Jividen, RN, BSN, is a trained neuro/trauma, and emergency room nurse turned healthcare writer. As a journalism major, she combined her love for writing with her passion for high-level patient ...

Black toenails are usually the result of toenail injury. However, there are other things that can cause a black toenail, including fungal or bacterial infections. Most cases of black toenails aren’t ...

If you’ve been ramping up your running routine, you’re probably bracing yourself for a few of the unpleasant but common side effects of increasing your mileage—blisters, muscle tightness, and next-day ...

Black toenails can result from an injury, a fungal infection, or pigmentation changes over time. More serious causes include heart disease or melanoma. Treatment for black toenails will vary depending ...

I had the same problem during my first London Marathon. Now I slip a bit of padding under the tongue of my shoe to stop my toes sliding forward, and black toenails are a thing of the past. What works ...