Subungual hematoma or bleeding under a nail plate, is a purple mark under the nail due to bleeding or bruising. Subungual hematoma results in painful or unnoticed purplish-black discoloration. The discoloration may persist for months as the nail carries the blood with it as it grows out.
Subungual hematoma is usually caused by a traumatic injury as in hitting your thumb with a hammer or stubbing a toe. Subungual hematoma can also occur from wearing tight-fitting shoes which trap blood in the toes leading to an increased pressure within the blood vessels of the toes. In either case, the injury leads to the breakage of small blood vessels underneath the nail which leak blood into a potential space below the nail that causes discoloration of the nail and intense pressure.
Initially the injury may only hurt. The nail may feel sore or tender to the touch. As the blood pools under the nail the pressure from the blood can cause severe pain. The pressure caused by blood underneath the nail may result in the affected nail lifting off the finger or toe. The color under the nail will change over time initially red to purple and later to dark brown and black as the blood clots. The pain usually resolves days after the injury and the nail looks worse than it feels.
There are a few reasons to seek medical attention: if bleeding does not stop, if the pain becomes too intense, or if there is significant injury to the base of the nail. Depending on the manner of injury, issues to be aware of would be; a deep cut or laceration to the skin of the finger or toe underneath the nail that may require stitches as well as taking an x-ray to determine if the bone of the finger or toe involved is broken. If necessary the pressure caused by the hematoma can be resolved by a medical professional using a technique called trephination. This is done by using a sharp instrument to pierce the nail and drain the blood which relieves the pain. Drainage or removing the nail is discouraged from being attempted by the public because this could lead to further complications of infection, additional trauma, slowing of the healing process, or leaving the finger or toe vulnerable.
Over the course of several months a new nail replaces the damaged, discolored nail. There usually is no need for further treatment or follow up.
Subungual hematoma treatment
Usually the treatment is minimal and consists of rest, ice, elevation, and compression of the finger or toe. Over the counter pain medication can be given if needed. Elevation and the use of ice help to reduce the swelling and further pain. Placing ice directly on the affected nail could cause further injury, so wrapping ice in a cloth towel and applying it to the affected area works best. Compression can further reduce the bleeding underneath the nail.
What you can do for subungual hematoma:
- Apply ice for 20 minutes every 2 hours on the first day, then 3 to 4 times a day after that.
- To reduce the throbbing, keep your hand or foot above the level of your heart.
- Take prescription pain relievers as directed. Or you can use ibuprofen or naproxen to reduce pain and swelling. Acetaminophen helps with pain, but not swelling. You can buy these pain medicines without a prescription.
- NOTE: Talk with your doctor before using these medicines if you have heart disease, high blood pressure, kidney disease, or have had stomach ulcers or internal bleeding in the past. DO NOT take more than the amount recommended on the bottle or by your doctor.
Regardless of treatment the hematoma will eventually be resorbed by the body and a new nail will grow out. On average the nail takes 6 to 9 months to grow completely out. Toenails take about 12 months to grow back. A complication to be aware of is damaging the cells that re-grows the nail (the nail matrix). If the nail matrix is damaged the nail will grow incorrectly or may not re-grow a nail. The new nail will probably have grooves or ridges and be somewhat misshapen. This may be permanent.
For more serious nail injuries, you should go to an urgent care center or the emergency room. They will stop the bleeding and clean the wound. Usually, the nail and finger or toe will be numbed with medicine before it is treated.
- For a larger bruise, your doctor will create a small hole in the nail.
- This will allow fluid to drain out and relieve the pressure and pain.
- If the bone is broken or the bruise is very large, the nail may need to be removed and the nail bed repaired.
If you broke a bone in your finger or toe along with the nail injury, it will take about 4 weeks to heal.
Draining subungual hematoma
Small or painless hematomas and hematomas that are already draining need not be trephined. Hematomas confined to the lunula should not be trephined. If you suspect underlying nail-bed injury or fracture of the phalanx, trephining should not be attempted.
Draining is indicated to relieve pain caused by subungual hematomas when the nail edges are unaffected. The decision to perform this procedure is based on the degree of pain, rather than the size of the hematoma. The video reviews the technique and equipment required.
Choose a sterile, disposable, 23-gauge double-bevel 1-inch needle. Note that when choosing the needle, there is a trade-off between bore size and bevel length. Hold the needle between the thumb and third finger and steady the needle on top of the hub with your index finger. Place the needle over the nail and the hematoma, choosing a position by comparing the landmarks with the corresponding contralateral fingernail so as to avoid the lunula. With the thumb and third finger, rotate the needle back and forth. The double bevel acts as a drill, slowly penetrating the nail. No pressure needs to be applied to the needle by the index finger. Just as the needle penetrates the nail, a small bead of blood will appear in the drilled hole, telling the doctor to slow down and complete the last of the drilling maneuver with extra care to avoid the underlying nail bed.