A subungual hematoma, also known as blood under the nail, is a condition characterized by a small collection of blood between the nail bed and the nail. The area initially appears purple but eventually turns black within a few days. Subungual hematomas can occur due to a single injury to the nail or from repetitive trauma, causing intense throbbing pain. Although the condition can be quite uncomfortable, it is not considered a serious medical issue. There are various treatment options available, depending on the size of the hematoma, to alleviate the symptoms of subungual hematoma.
Causes of Subungual Hematomas
Subungual hematomas occur when there is bleeding under the nail bed. This condition can be caused by various factors, including acute injuries and repetitive trauma.
One common cause of subungual hematomas is a single, acute injury that crushes the tip of the finger or toe. This can happen due to accidents such as a blow from a hammer, the impact of a heavy object, or accidentally slamming the finger in a door.
Repetitive trauma to the nail is another cause of subungual hematomas. Wearing ill-fitting shoes over a prolonged period of time can lead to this condition. Athletes, in particular, are at risk due to the running motion that forces their toes into the front of the shoe. This phenomenon is sometimes referred to as “runner’s toe.”
Regardless of the cause, trauma to the nail bed is what triggers subungual hematomas. This trauma causes the small blood vessels in the area to bleed, resulting in the accumulation of blood underneath the nail.
Symptoms and Signs
Subungual hematoma is often accompanied by several noticeable symptoms. The primary symptom is severe pain experienced at the nail bed. Due to the restricted area beneath the nail, the accumulation of blood increases pressure, leading to a throbbing sensation. As time progresses, a blackish discoloration will appear under the nail. Additionally, the nail may begin to lift away from the nail bed. The nail bed has a rich blood supply and a high concentration of nerves, which explains the intense pain associated with subungual hematomas. Since the nail is firmly attached to the tip of the finger or toe, there is minimal fatty tissue available to absorb the accumulating blood. Consequently, the bleeding exerts pressure on the nerve endings, intensifying the pain and causing throbbing sensations.