Subungual Hematoma Facts
A subungual hematoma is a collection of blood in the space between the nail bed and fingernail.
Subungual hematomas result from a direct injury to the fingernail.
The pressure generated by this collection of blood under the nail causes intense pain.
Subungual Hematoma Causes
Subungual hematomas most commonly form after a crush-type injury to the tip of the finger or toe.
This injury can occur in many ways:
Hitting your finger with a hammer
Dropping a heavy object on your toe
Closing your finger in a door
Subungual Hematoma Symptoms and Signs
Blood underneath the nail of either a finger or toe is a subungual hematoma.
You will have a discoloration of red, maroon, or other dark color beneath the nail after an injury.
The most common symptom is intense pain.
Pressure generated between the nail and the nail bed, where the blood collects, causes this pain.
The pain may also be caused by other injuries such as a fracture (break) to the underlying bone, a cut in the nail bed, or bruising to the finger or toe itself.
When to Seek Medical Care for a Subungual Hematoma
If the pain is mild and the hematoma (blood collection) is less than 25% of the area under the nail, then home care can be considered.
If the hematoma is 50% or more of the underlying nail area, then medical attention is required.
If the injury that causes the subungual hematoma is severe enough to cause intense pain and tenderness, you should seek medical attention. The mechanism of injury for this condition can cause a fracture to the bone at the end of the finger or toe or a laceration to the nail bed under the nail that may require further medical attention.
Subungual Hematoma Diagnosis
Often, an X-ray is taken to look for a fracture (break) to the underlying bone.
X-rays do not provide any information regarding the bleeding or hematoma formation underneath the nail.
Nail bed evaluation
Depending on the type of injury and the degree of the injury and how much blood forms under the nail, the doctor may decide to remove the nail to check the nail bed for lacerations (cuts). While it used to be customary to have the nail removed to examine the nail bed for lacerations or injuries, this is no longer routine practice if the nail edges or margins are intact.
Subungual Hematoma Home Remedies
Ice, elevation (keeping your arm or leg above the level of your heart), and pain medications are recommended for minor hematomas. Wrap ice in a towel and do not apply ice directly to skin. A bag of frozen vegetables (corn or peas) wrapped in a towel works well.
If the hematoma involves more than 50% of the area of the nail, then medical attention is needed.
If the nail was removed by the injury and the nail bed wasn't cut, the following home treatment is recommended until the nail bed begins to be less sensitive, usually in seven to 10 days.
Twice daily soaks with antibacterial soap and water for 10-15 minutes
After soaks, apply a dry, sterile bandage (Band-Aid)
Treatment of an Uncomplicated Subungual Hematoma
A painless and small subungual hematoma usually requires no treatment. However, the pressure generated by pooled blood under the nail can be extremely painful. To relieve the pain, doctors perform decompression, also called trephination, which allows the underlying blood to drain, relieving pressure and pain to the area.
After numbing the affected finger or toe with a nerve block, doctors commonly use several decompression methods to drain a subungual hematoma:
Cautery. A heated wire (electrocautery device) is used to burn the hole or holes during a painless procedure that takes only a few seconds.
Paper-clip method. A heated paper clip is placed over the center of the hematoma to melt a hole into the nail.
Needle. A large-diameter needle is used to perforate the nail.
Treatment for Subungual Hematoma
Several techniques are used to drain the blood beneath the nail. This procedure is also called releasing the hematoma or trephination.
No single technique is preferred.
How your hematoma is drained depends on the experience of the doctor and where it is done.
Occasionally, the finger or toe is numbed with a digital block. (Your fingers and toes are called digits.) Some doctors (health care professionals) opt not to numb up the digits as the injection itself can cause as much if not more pain than the actual drainage of the hematoma.
A numbing medication such as lidocaine is injected at the bottom of your finger or toe.
Injecting the medication here numbs the entire digit.
As soon as your finger or toe is numb, the procedure can take place.
The following are commonly used methods for draining your hematoma:
Cautery: A battery-operated device is used to burn a hole in the nail until the blood is reached and drains out of the hole. This technique should not be used if the patient is wearing artificial acrylic nails which might be flammable.
Needle: A large diameter needle is used to drill or bore into the nail to create a hole to allow the blood to drain out.
Paper clip: This technique, although an older one, is still used by some practitioners. A paper clip is opened so that the pointed end is free. Then the pointed end is heated up, usually by passing it through a flame, and used to burn through the nail. This technique uses a combination of the cautery method and the needle method.
Subungual Hematoma Follow-up
After the subungual hematoma has been drained, follow-up is usually not necessary.
Antibiotics are not routinely needed after a subungual hematoma is drained.
If the nail was removed and a cut in your nail bed was stitched closed, you should see your doctor in 48-72 hours for re-examination.
Usually, the type of sutures (stitches) placed will dissolve, so removal is not needed.
If non-dissolvable sutures (nylon) are placed in a nail bed laceration, they need to be removed in about seven days in the emergency department or by your doctor.
Close monitoring is still recommended.
Subungual Hematoma Prevention
Use common sense and practice other safety-minded actions to prevent getting your fingers slammed in doors or dropping heavy objects on your toes.
Steel-toed shoes are important safety equipment to wear on certain high-risk jobs such as construction.
Watch children's hands as you open and close car doors.
Give your full attention to the task at hand. Finger injuries often happen when the person using the tool is distracted.
Don't lift something you cannot handle alone. Find people to help you carry heavy objects to avoid dropping them on your toes.