Do you have sore nails and wonder what that means? Often benign, nail pain can nevertheless indicate conditions requiring medical attention. Understanding the potential causes of this pain can help you respond appropriately and avoid complications. Common Causes of Nail Pain Trauma is the most common cause of nail pain. A direct blow, such as hitting with a hammer or getting your finger stuck in a door, can result in a subungual hematoma, commonly known as a “black toenail”. This may require medical drainage if the pain is severe or the finger is swollen and difficult to move. Other Sources …