Watch: US Dermatologist Reveals One Nail Sign You Should Never Ignore

Nails can give important clues about your health and now a US-based dermatologist is “begging” her social media followers to check their nails for a vertical line, which could indicate a rare but serious type of skin cancer. In an Instagram video, Dr Lindsey Zubritsky asked her followers to check if they have a dark-pigmented vertical streak going down their nail. If yes, she urged users to get it checked immediately as it could indicate a subungual melanoma, which is a type of skin cancer. 

“It could potentially be a very serious form of skin cancer called a subungual melanoma,” Dr Zubritsky said. “While it’s not common, it can be easily missed if you don’t know what you’re looking for,” she added. 

Further, Dr Zubritsky said that not all dark streaks on nails are subungual melanomas or dangerous. A longitudinal melanonychia, for example, is a brown or black vertical nail streak that’s typically benign, she explained. “It’s more likely that you have the benign streak. It’s a lighter streak. It’s not changing. It’s found on multiple nails,” the dermatologist said. 

The doctor also drew the distinction between a subungual melanoma and a subungual hematoma, which is when blood pools under the nail after a trauma like getting a finger caught in a door or accidentally hitting it with a hammer. Hematomas typically grow out over time.