Many runners are all too familiar with black toenails. The condition involves bruising, blistering, or bleeding beneath your nail from repetitive trauma, either from the top of your shoe rubbing. There are many causes of black or dark toenails, but the most common cause is trauma. When trauma occurs to a nail resulting in discoloration it is referred to as a subungual hematoma, which simply means there is a collection of blood underneath the nail. Black Toenail Common Causes. If your toenail turns black, its most likely a bruise under the nail, technically called a subungual hematoma. You can get it from stubbing a toe or from footwear. How to Treat a Black Toenail. Having part or all of a toenail turn black can be alarming. Fortunately, the causes of black toenails are usually not serious, and the condition is often easy to treat. The best treatment will depend on the. Everyone has had a black toenail, at least once in our lives. In the majority of the cases, as you will have the opportunity to read below, the black toenail appears after an injury. However, there are other causes that can lead to the appearance of a black toenail, such as the intense physical effort. Why are your toenails black? A fungal infection, trauma, or even an underlying condition like kidney disease can be the cause of your black toenail. Usually you can treat your nail at home, but in. Black toenails can be unsightly and painful. Sometimes, nails become black because of a traumatic injury, but other nail changes may reflect an underlying condition. Find out some of the causes of. NATURALLY BLACK TOE NAILS !!!!! For as long as I could remember. My toe nails have always been dark. I am a chocolate complexion woman. Every since I was a child, my toenails have been a dark brown color. Ive always hated them, because all the other kids toenails were clear and white and I had these dark brown/black toe nails. Black toenails are caused by trauma to the nail. Common causes of toenails turning black include ill-fitting shoes, fungus, dropping an object on the toe and cutting the nail too short. Impact to the toenail causes bleeding underneath the nail's surface. Part or all of the toenail may turn black. Black Toenail Fungus Treatment. There are many remedies for black toenails caused by toenail fungus. The sooner that you start treatment, the better. So, pay attention to the early symptoms, such as discoloration or a strange odor. If your nail has already turned black, there are still things that can be done.