A black toenail resulting from an injury is common, often causing concern due to its striking appearance. While typically not a serious medical emergency, it warrants attention and proper care. Understanding such an injury is important for self-management and knowing when to seek professional medical advice.
Understanding the Discoloration
The medical term for a black toenail caused by trauma is a subungual hematoma. This condition arises when blood vessels beneath the nail plate are damaged by an impact or crushing force. The injury causes capillaries to break, leading to bleeding into the confined space between the nail and the nail bed.
The trapped blood accumulates under the nail, creating pressure. This pooling blood produces the characteristic dark discoloration, which can appear red, maroon, dark purple, or black. A subungual hematoma is similar to a bruise on other parts of the body, but the blood is contained beneath the rigid nail plate.
Initial Steps and At-Home Care
After a toe injury, several steps can help manage discomfort and prevent complications. Apply ice to the affected toe to reduce swelling and pain. Wrap an ice pack or a bag of frozen vegetables in a cloth and apply it for 10 to 20 minutes at a time, with breaks. Elevating the foot above heart level also minimizes swelling and pressure in the injured area.
Resting the injured toe and limiting physical activity prevents additional trauma and promotes healing. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can be used to manage pain. Keep the area clean and protected from further injury, perhaps by wearing comfortable, loose-fitting shoes that do not put pressure on the toe.
When Professional Medical Attention is Needed
While many black toenail injuries can be managed at home, certain symptoms indicate a need for professional medical evaluation. Severe or throbbing pain that persists or worsens despite home care may suggest significant pressure from the accumulated blood, which may require drainage. Signs of infection, such as increasing redness, warmth, swelling around the nail, pus draining from under the nail, or red streaks extending from the wound, warrant immediate medical attention.
If a large portion of the nail (generally more than half) is discolored, or if the nail appears lifted or detached from the nail bed, a doctor should assess the injury. A suspected fracture of the toe bone, indicated by deformity, intense pain, or an inability to walk or bear weight, also warrants prompt medical evaluation. Any discoloration that appears without a known injury or changes in color or size over time should be checked by a healthcare provider to rule out other causes.
The Healing Journey and Nail Changes
The healing process for a subungual hematoma is gradual, involving the natural growth of the toenail. The discolored area will not disappear quickly; instead, it will slowly move forward as the new, healthy nail grows from the base. This process can take six to nine months for the entire toenail to be replaced.
As the new nail grows, the old, discolored portion may loosen or even fall off. This is a normal part of the healing process and usually not a cause for concern. While the nail grows out, temporary changes such as thickening, ridging, or a rough texture may be observed, especially if the nail matrix was affected by the trauma. In some cases, if the damage to the nail matrix is significant, the new nail may grow back with a slightly altered shape or thickness.