What Is a Subungual Hematoma, and How Do You Treat It?
Key takeaways:
A subungual hematoma is a bruise that forms under the nail after trauma.
Subungual hematomas can be very painful, but draining them can provide pain relief.
Most subungual hematomas heal well, but there’s a risk for complications like nail loss and infection.
Have you ever dropped something on your toe or slammed your finger in a door? If you’ve had trauma to your nail, you may notice that it turned purple, blue, or black. Just like you can get a bruise on your ribs or another body part, you can also get a bruise under your toenail or fingernail. This is called a “subungual hematoma.”
Subungual hematomas are very common. While they’re very painful, they usually aren’t dangerous. If you have a subungual hematoma, here’s everything you need to know about how to care for your injured finger or toe.
What causes a subungual hematoma?
Your nail bed is the tissue directly beneath your nail. The nail bed contains lots of nerve endings and blood vessels. These blood vessels give your nails their pink tinge.
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When you have a direct trauma to your nail, these blood vessels break and start to bleed. Since your nail is connected to your finger or toe on all sides, the blood has nowhere to go. It’s trapped underneath your nail. The pressure from the blood building up causes pain. The blood also makes your nail look blue, purple, black, or brown.
Some hematomas are quite large and cover almost the entire nail. Other hematomas are smaller and don’t cause pain.
Subungual hematomas can happen with minor or indirect trauma to the nail, like:
Walking long distances in shoes that are too tight
Running long distances
Playing tennis
They can also happen after more direct trauma like:
Dropping a heavy object on your toenail
Kicking a hard object
Slamming your fingernail in a door
Hitting your nail with a hammer
Subungual hematoma pictures
Here are some subungual hematoma pictures to help you know what to look for.
Is there treatment for a subungual hematoma?
If you develop a subungual hematoma, your primary care provider or urgent care professional can drain the blood from underneath your nail. This procedure is called “nail trephination.” Trephination allows the blood to escape and relieves pressure and pain.
But in order to work, blood needs to be drained before it starts to clot — usually within 48 hours of when you injured your nail.
During trephination, you’ll receive a digit block — a local anesthetic — so you don’t feel pain during the procedure. Then, a healthcare professional will create a small hole in your nail using one of these tools:
A cautery device (a tool that uses electricity to produce heat)
A small needle
A biopsy tool (a tool with a small wire circle or loop at the end)
A mesoscission device (a tool that creates a small cut in your nail plate)
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Unless you have a more serious injury, you won’t need to have your nail removed. You shouldn’t try to drain a subungual hematoma yourself. This can lead to serious infection and permanent damage to your nail or finger.
You can also try home remedies to help with pain and recovery, like:
Rest
Ice or cold compresses
Gentle compression
Elevating your finger
Pain medications, like acetaminophen or ibuprofen
How do you know if you need to drain a subungual hematoma?
Not everyone needs drainage of a subungual hematoma. If the hematoma is small and not causing much pain, you can often let it heal at home. But you should seek medical care in the following cases:
The hematoma covers half of your nail or more.
There’s an injury or cut to your nail fold (the sides and bottom of your nail).
You’re experiencing a lot of pain.
There’s bleeding through or around your nail.
You have any additional injuries to your finger or toe.
There’s a serious injury to the base of your nail.
If you have a simple subungual hematoma — meaning a hematoma but no other bleeding or digit injury — your primary care provider or an urgent care center may be able to perform a drainage.
But if you have signs of a more serious injury (like a fracture or very deep cut), you should go to the emergency room. You may need more comprehensive care or a consultation with a hand surgeon. Additional tests and treatment you may get include:
An X-ray
A thorough wound cleaning
Stitches
Antibiotic pills
How do you care for your nails after draining a subungual hematoma?
Caring for your nails after subungual hematoma drainage is pretty easy. All you need to do is:
Keep the area as clean as possible.
Avoid soaking your nail, because this can lead to infection.
Watch for any signs of infection like redness, swelling, or oozing pus.
If you see any signs of infection, see a healthcare professional right away. If you have an additional injury, like a fracture, you may need further care — like splints and a follow-up with a specialist.
How long does it take a subungual hematoma to heal?
It can take several months for a subungual hematoma to fade completely and for a healthy nail to regrow.
Hematomas heal naturally over time, even if you don’t have them drained. The body will break down and absorb the blood under the nail.
What complications can occur with a subungual hematoma?
Most subungual hematomas heal well over time. But sometimes complications do happen, including:
Nail loss: If there isn’t damage to the nail matrix (the cells that regrow the nail), your nail should grow back normally. But if there’s damage, your nail could fall off. While your nail may grow back, it might grow back with a different shape. If there’s more serious nail matrix damage, the nail may not grow back at all.
Discoloration of the nail: You might notice nail discoloration as your hematoma heals. But, as healing progresses, most change in color should go away.
Infections: Any break in the skin can lead to a nail infection. It’s important to keep the area clean and watch for signs of infection.
Frequently asked questions
A subungual melanoma is a serious type of skin cancer that develops underneath the nail.
Subungual melanoma may look like a brown or black streak or spot on the nail. It can be confused with a subungual hematoma. So, it’s important to get the right diagnosis. If you’re not sure whether you have a subungual hematoma or melanoma, see a healthcare professional right away.
If you want to drain a subungual hematoma, it should be done within 48 hours after the injury. After this, the blood will start to clot, making it hard to drain.
Pain from a subungual hematoma usually goes away within a few days. If your pain is severe or lasts longer than this, see your primary care provider. They’ll check for infection, fracture, and other injuries that could be causing pain.
The bottom line
Subungual hematomas are bruises that form under a nail after trauma. These hematomas can be very painful. They can also happen with more serious finger or toe injuries. If the hematoma is small and doesn’t cause pain, then you can take care of it at home with rest, ice, and pain medication. But if you have a large hematoma, a lot of pain, or any additional injuries, you should seek medical care for drainage and additional treatment.
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Images used with permission from VisualDx (www.visualdx.com)
References
American Osteopathic College of Dermatology. (n.d.). Subungual hematoma.
Bai, J. (2020). Consult corner: Laceration through the nail bed. American Society of Plastic Surgeons.
Ciocon, D., et al. (2006). How low should you go: Novel device for nail trephination. Dermatologic Surgery.
DermNet. (2011). Melanoma of nail unit images.
de Villeneuve Bargemon, J. B., et al. (2020). A simple painless technique to drain subungual hematoma. Journal of the American Academy of Dermatology.
Kee, C., et al. (2021). Phalanx fracture. StatPearls.
Mole, R. J., et al. (2023). Subungual melanoma. StatPearls.
Oztas, M. O. (2010). Clinical and dermoscopic progression of subungual hematomas. International Surgery.
Pingel, C., et al. (2023). Subungual hematoma drainage. StatPearls.
Streitz, M. J. (2020). How to do nail trephination. MSD Manual Professional Version.
