A smashed finger is a common, painful occurrence, often resulting from accidents like slamming a door or dropping a heavy object. This trauma can lead to a subungual hematoma, where blood collects beneath the nail. While many such injuries are minor and resolve on their own, understanding when to seek professional medical attention is important.
What is a Subungual Hematoma?
A subungual hematoma is a collection of blood that forms underneath a fingernail or toenail. It typically results from direct trauma, such as crushing a digit in a door or striking it with a hammer. The injury causes blood vessels beneath the nail plate to rupture and leak blood into the confined space between the nail and the nail bed.
Symptoms include intense, throbbing pain and a noticeable discoloration under the nail. The pain arises because the trapped blood creates pressure against the sensitive nail bed. The discoloration can appear black, blue, purple, or maroon.
When to Seek Professional Medical Care
While some subungual hematomas can be managed at home, certain signs indicate the need for professional medical evaluation. Persistent, severe, or worsening throbbing pain that is not relieved by over-the-counter pain medication warrants immediate attention. Such pain suggests significant pressure that may require intervention.
A medical professional should assess the injury if the hematoma covers generally more than 25% to 50% of the nail surface. This is particularly true if the injury also involves signs of a possible underlying bone fracture, such as deformity of the finger or toe, an inability to move the digit, or severe swelling. An X-ray might be necessary to rule out a fracture.
Medical care is also important if there is a suspected laceration to the nail bed, indicated by a split or torn nail, which suggests deeper tissue damage. Watch for signs of infection developing around the injury site days after the initial trauma, including increased redness, swelling, warmth, pus, or fever. Uncontrollable bleeding or any uncertainty about the injury’s severity also means it is time to consult a healthcare provider.
Understanding Drainage for Pressure Relief
Draining a subungual hematoma, a procedure known as trephination, aims to relieve the intense pressure and pain caused by trapped blood. This is achieved by creating a small hole in the nail plate, allowing the accumulated blood to drain out. Medical professionals typically perform this using a sterile needle, an electrocautery device, or a scalpel blade to carefully puncture the nail.
The procedure is often quick and can provide immediate pain relief once the pressure is released. Attempting to drain a subungual hematoma at home carries significant risks. Doing so can lead to serious infection, further injury to the nail bed, or inadequate pain relief due to improper technique or non-sterile conditions. A healthcare professional possesses the necessary sterile equipment and expertise to safely assess the injury and perform the drainage if appropriate.
Aftercare and What to Expect
After a subungual hematoma, whether drained or not, proper aftercare helps manage discomfort and promote healing. Over-the-counter pain relievers, such as ibuprofen or acetaminophen, can alleviate any remaining pain. Keep the injured finger or toe clean and protected with a loose bandage to prevent infection.
Monitor the injury for signs of infection, such as increased redness, swelling, warmth, or pus. If these symptoms appear or if pain worsens, seek further medical attention. The discolored nail will gradually grow out as a new, healthy nail replaces it. This process can take several months, typically 4 to 6 months for fingernails and 6 to 18 months for toenails. The old nail may lift or fall off as the new nail grows underneath.