A subungual hematoma is a collection of blood under the fingernail caused by a direct injury to the nail. This blood collection puts pressure on the nailbed, causing intense pain. It is usually treated by draining the blood out through a hole made in the nail. Medical attention is needed if the hematoma involves over 25% of the nail area or the injury is severe. After draining the blood, the nail hole will grow out over time but there is a risk of permanent nail deformity from damage to the nailbed.

1. Subungual Hematoma (Bleeding Under Nail)
Subungual Hematoma Overview
A subungual hematoma is a collection of blood in the space between the nailbed and
fingernail. Subungual hematoma results 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:
o Hitting your finger with a hammer
o Dropping a heavy object on your toe
o Closing your finger in a door
Subungual Hematoma Symptoms
• Blood underneath the nail of either a finger or toe is a subungual hematoma.
o
o 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.
o
o Pressure generated between the nail and the nailbed, where the blood
collects, causes this pain.
o
o The pain may also be caused by other injuries such as a fracture
(break) to the underlying bone, or bruising to the finger or toe itself.
When to Seek Medical Care
If the pain is mild and the hematoma (blood collection) is less than 25% of the area
under the nail, then home care is recommended.

2. If the hematoma is 25% 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 or if the blood collection beneath the nailbed occupies 25% or
more of the nail area, 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 nailbed under the nail that may require further medical attention.
Exams and Tests
• X-ray
o
o Often, an x-ray is taken to look for the possibility of a fracture (break)
to the underlying bone.
o
o X-rays do not provide any information regarding the bleeding or
hematoma formation underneath the nail.
• Nailbed evaluation
o
o 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 nailbed for lacerations (cuts).
Subungual Hematoma Treatment Self-Care at Home
• Ice, elevation (keeping your arm or leg above the level of your heart), and
anti-inflammatory medications, such as ibuprofen, are recommended for
minor hematomas. Wrap ice in a towel and do not apply ice directly to skin. A
bag of frozen vegetables wrapped in a towel works well.
• If the hematoma involves more than 25% of the area of the nail, then medical
attention is needed.
• If the nail was removed by the injury or the doctor and the nailbed wasn't cut,
the following home treatment is recommended until the nailbed begins to be
less sensitive, usually in 7-10 days.
o Twice daily soaks with antibacterial soap and water for 10-15 minutes

3. o After soaks, application of a topical antibiotic ointment (such as Neosporin)
and a dry sterile bandage (Band-Aid)
Medical Treatment
• Several techniques are used to drain the blood beneath the nail. This
procedure is also called releasing the hematoma.
o
o No single technique is preferred.
o
o How your hematoma is drained depends on the experience of the
doctor and where it is done.
• Frequently, the finger or toe is numbed with a digital block. (Your fingers and
toes are called digits.)
o
o A numbing medication such as lidocaine is injected at the bottom of
your finger or toe.
o
o Injecting the medication here numbs the entire digit.
o
o As soon as your finger or toe is numb, the procedure can take place.
• The following are commonly used methods for draining your hematoma:
o
o Cautery: A battery-operated device is used to burn a hole in the nail
until the blood is reached and drains out the hole.
o
o 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.
o 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.

4. Next Steps Follow-up
• After the subungual hematoma has been drained, follow-up is usually not
necessary.
• If the bone beneath your nail was broken, you may have been started on
antibiotics, and you should follow up with your doctor.
• If the nail was removed and a cut in your nailbed was stitched closed, you
should see your doctor in 48-72 hours for re-examination.
o
o Usually, the type of sutures (stitches) placed will dissolve, so removal is
not needed.
o
o If nondissolvable sutures (nylon) are placed in a nailbed laceration,
they need to be removed in about 7 days in the emergency department
or by your doctor.
o
o Close monitoring is still recommended.
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.
Outlook
• After the subungual hematoma is drained, the pressure beneath the nail is
relieved, and the pain decreases significantly.

5. • The hole formed in the nail will obviously remain and grow out at the rate that
the nail normally grows.
• One possible risk and long-term complication of a subungual hematoma is a
nailbed laceration (cut).
o
o If trauma is severe (for example, an open wound of the surrounding
soft tissue including the nail and nailbed), the nailbed laceration can be
stitched closed after the nail is partially or completely removed.
o
o If the skin beneath the nail is lacerated, similar to any other skin cut, it
may not heal properly.
o
o This complication can result in deformity of the nail and the nail
growth.
o
o The deformity may be temporary and go away after the nail grows out,
or it may be permanent, and you may have an obviously deformed nail
forever.
o
o If you do not seek medical attention at all for a subungual hematoma
(not recommended), and sometimes even if you do, and a significant
injury occurs under the nail, the nail may completely fall off as it grows
out as part of the natural healing process.
o
o Despite best efforts by doctors and yourself at home, nail deformity
and permanent abnormalities can result from such injuries.
Multimedia
File 1: A thumb after it was hit with a large hammer. Notice that the dark
discoloration beneath the nail takes up more than 75% of the area. This is blood.
This hematoma required drainage to relieve the pressure.

6. File 2: The battery-operated cautery unit and its tip when it is activated. Notice the
red hot area used to burn the hole in the nail.
File 3: The process of burning a hole in the nail to relieve the hematoma. Notice the
blood draining from the hole after the hole was formed with the cautery unit's hot
tip. The finger has been numbed prior to this procedure.
File 4: The same thumb after it has been drained. Notice the hole in the nail and the
blood draining from the hole. The large dark area beneath the nail (the hematoma)
is practically gone.
File 5: An example of a nail with a subungual hematoma that occupies less than 25%
of the nail area. This hematoma did not require drainage.

7. File 6: The same subungual hematoma 3 and one-half weeks after the original injury.
File 7: A paperclip opened for use in draining a subungual hematoma. The open end
would be heated to allow it to make a hole in the nail.