A bruised fingernail, known medically as a subungual hematoma, is a pool of blood trapped between your nail and the nail bed underneath. It happens when a direct blow or crush injury breaks tiny blood vessels beneath the nail. The buildup of blood creates pressure, which is what causes that intense, throbbing pain. Most bruised nails heal on their own over several weeks, but how you treat one in the first hours and days makes a real difference in pain and recovery.
What’s Actually Happening Under the Nail
When you slam your finger in a door, drop something on it, or catch it in a hinge, the impact ruptures small blood vessels in the nail bed. Blood leaks out but has nowhere to go because the hard nail plate is sitting on top. As more blood accumulates, it pushes against the sensitive tissue of the nail bed, creating that dark blue, purple, or black discoloration you can see through the nail.
The pain is directly related to pressure. A small bruise that covers a fraction of the nail may ache but remain tolerable. A larger hematoma covering half or more of the nail surface can produce severe, pulsing pain because of how much pressure the trapped blood exerts. That pressure distinction is also what determines whether you can manage this at home or need medical help.
Immediate First Aid Steps
The first thing to do is apply ice. Wrap an ice pack or bag of frozen vegetables in a thin towel and hold it against the injured finger for 10 to 20 minutes. Then remove it for at least 20 minutes before reapplying. You can repeat this cycle two or three times within the first six hours. Ice slows bleeding under the nail and reduces swelling, which helps limit the size of the hematoma.
Elevate your hand above heart level whenever you can during the first day or two. This is easy to overlook but genuinely reduces throbbing. Resting your hand on a pillow while sitting or holding it up while walking makes a noticeable difference.
For pain, over-the-counter options like ibuprofen, naproxen, or acetaminophen all work. Ibuprofen and naproxen also reduce inflammation, which can help with swelling around the nail. If the pain is manageable with these steps and the bruise covers less than about half the nail, you can likely treat this entirely at home.
When You Need Medical Drainage
If the bruise covers a large portion of the nail and the pain is severe or getting worse, a healthcare provider can drain the blood through a procedure called nail trephination. This works best within 24 to 48 hours of the injury, so don’t wait several days hoping it will improve on its own if the pain is significant.
The procedure is quick and done in an office or urgent care setting. Your provider positions a heated device, a needle, or a specialized tool over the center of the bruise and applies gentle pressure to create a small hole through the hard nail plate only, not the tissue beneath. Blood drains out immediately, and the pressure relief is often dramatic. You may notice some continued drainage through the hole for the next 24 to 36 hours, which is normal.
Do not try to drain a bruised nail yourself with a heated paper clip, safety pin, or any household object. This is a common suggestion online, but puncturing your nail without sterile technique risks introducing bacteria directly into the wound, potentially causing a serious infection in the nail bed or bone.
Signs That Suggest a More Serious Injury
A bruised nail sometimes comes with a fracture of the fingertip bone underneath. These fractures are common with crush injuries and don’t always feel dramatically different from a bad bruise. If you notice any of the following, it’s worth getting an X-ray:
- Severe swelling that extends well beyond the nail into the fingertip or finger
- Deformity or an unusual angle to the fingertip
- Inability to bend or straighten the end of the finger
- A bruise covering more than half the nail, which older guidelines have long flagged as a reason to check for a nail bed laceration underneath
Current practice has shifted somewhat. Even with a large hematoma, if the nail itself is still firmly attached and the surrounding skin and tissue look intact, the nail doesn’t necessarily need to be removed to check beneath it. But a provider should still evaluate the injury to make that call.
Caring for the Nail as It Heals
Keep the finger clean and dry. If the nail was drained, your provider will likely bandage it. Change the dressing daily or whenever it gets wet, and watch for signs of infection: increasing redness, warmth, swelling, pus, or pain that worsens after the first few days instead of improving.
Protect the finger during activities. A simple finger splint or buddy-taping it to the neighboring finger can prevent re-injury during the first week or two. Avoid gripping heavy objects with that hand when possible.
The discoloration itself is harmless. As the bruise ages, it may shift from dark purple to brown or reddish-black. The blood will slowly grow out with the nail or be reabsorbed. There’s no way to speed this up cosmetically.
How Long Full Recovery Takes
Fingernails grow at roughly 0.1 millimeters per day, though this varies by finger, age, and overall health. A fully damaged nail takes about 4 to 6 months to completely regrow. One case study tracking regrowth after nail removal documented full replacement at 33 weeks (about 8 months), with broader research placing the range at 4 to 10 months depending on the severity and which finger is involved.
In many cases, the bruised nail stays attached and gradually grows out with the dark spot moving toward the tip over several months. Sometimes the nail loosens and partially or fully detaches. This looks alarming but is usually painless by the time it happens. A new nail is already growing underneath. If the nail does separate, keep the exposed nail bed covered with a bandage to protect it until the new nail covers the area.
Most bruised nails heal without any lasting change. In cases involving significant nail bed damage, the new nail may grow back with a slight ridge, bump, or texture difference. This is more common when the injury also involved a fracture or laceration of the nail bed beneath.