Last night I received a frantic text from a friend. Turns out that the tip of her finger got caught in the car door leaving her fingernail with a crescent shaped purple mark under her index fingernail. In addition to a bruiser and pain, she had some very valid questions for concern — especially since her wedding is just over 2 weeks away!!
How long will the purple mark/bruise last? First of all, bruises are made when our red blood cells leak out of our vessels. As these red blood cells break down, they cause the red to purple to yellowish discoloration. Bruises on the body usually disappear by 1-2 weeks time but the problem with a bruise underneath the nail is that some of the blood leaks out and gets caught under the nail. The fancy medical term we use for this is subungual hematoma. It’s a waiting game for the trapped blood to grow out with the nail. Fingernails grow at about a couple millimeters a month. So, be patient!
Will my nail lift off or fall off? If the bruise is pretty small, as was the case with my friend, the nail will likely stay in place. However, if a large area is involved, you may lose your nail. Think of it this way, the blood has created a barrier between your nail and the skin of your finger underneath.
Depending on where and how much trauma occurs on the finger, it can lead to a broken bone in the finger (in which case, you’d need an xray to figure that out). Also, if there’s a really large bruise or collection under the nail which causes a lot of pain, your doctor can drain it for you for your comfort. So, if you have any concerns, you may need to go see urgent care, the emergency department or your primary physician.