MD Podiatrist Discusses Black Toenails

When your toenail turns black, you might wonder what’s happening and whether you should be worried. Not only is the discoloration an eyesore, but it can also be painful. Most commonly, a black toenail signals a subungual hematoma, or blood pooling under the nail due to an acute or repetitive trauma, Dan Michaels, DPM says. As far as acute injury, think: dropping something heavy on your foot or stubbing a toe.
 

In other cases, a black toenail could indicate a fungal infection under the toenail or, much less commonly, a melanoma (a type of skin cancer) in the toenail, Dr. Michaels says. “When more than 75 percent of the nail is black or blue, or there is tenderness on compression or a pressure sensation, it’s time to see a podiatrist,” he says. If indeed it’s a blood blister under the hard part of the toenail, your podiatrist may have to evacuate or drain it, Dr. Michaels says. “Do not attempt this on your own because you can potentially damage the nailbed beneath the blister,” he cautions.