We all stub our toes or accidentally hit our thumbs with a hammer once in a while, which leads to bruising on our nails, which is normal.

But if you happen to notice something that looks like a black stripe on one of your toenails or fingernails, you should probably go see a health professional to get it looked at.

The reason you shouldn’t ignore these signs is that melanomas, which are cancerous tissues on the skin, can develop under our nails.

This type of cancer usually affects people of African descent, but it can happen to people of any race or gender, so it’s best to keep an eye out for it.

If this kind of melanoma is detected, removing the growth and the nail usually takes care of the problem, but if it is not looked into and dealt with, this kind of cancer can spread to other organs in the body.

While we don’t usually hear about this kind of cancer, it ends up costing about 1,000 people their lives every year.

If you notice a dark stripe on your nail that has blurred borders, you should get it checked out immediately. Also, if the stripe changes in any way, that’s another warning sign.

Take a look at this video from CBS New York for more information.