A subungual hematoma occurs when an injury breaks open blood vessels under the nail, causing blood to collect and become trapped in one spot. It can affect both fingernails and toenails.

If a subungual hematoma is small and the pain is mild, it will usually resolve without treatment or complications.

However, if there is severe damage to the nail bed, or if the pain is unmanageable, a person should seek medical treatment.

Read on to learn more about subungual hematomas. This article looks at symptoms, causes, treatment options, and more.

A person may have a subungual hematoma if they have injured their finger or toe and:

  • there appears to be blood under the nail
  • the nail feels sore or tender
  • it feels like there is pressure under the nail
  • the nail is discolored

People with artificial nails may not be able to see a subungual hematoma. If a person feels intense pain and pressure, they may need to remove the artificial nail and examine the nail bed.

View the slideshow below for photos of subungual hematomas.

Learn more about nail bed injuries.

Possible causes of a subungual hematoma include:

In rare cases, a subungual hematoma may be due to a malignant tumor, such as melanoma or squamous cell carcinoma.

Learn about other conditions affecting the nails.

To assist with reaching an accurate diagnosis, the doctor may examine the nail using dermoscopy. It involves looking at the nail closely using a handheld instrument called a dermoscope.

The doctor may also order an X-ray to assess for possible fractures. They will also likely look for any signs of subungual melanoma, as it can cause changes in nail pigmentation.

Depending on the severity of the subungual hematoma, treatments may include home remedies and medical treatments.

Home remedies

Home remedies can help to manage a minor subugual hematoma while the injury heals.

Over-the-counter pain relievers can reduce discomfort and swelling. In addition, the RICE method can be useful for minor subungual hematomas. RICE stands for:

  • Rest: Rest the finger or toe and avoid using it where possible.
  • Ice: Use an ice pack to reduce swelling and pain.
  • Compression: Apply pressure, such as a wrap, to the area immediately to reduce the amount of blood that can pool.
  • Elevation: Keep the affected hand or foot elevated to reduce swelling.

Medical treatments

For more serious injuries, medical treatments may be necessary. Any significant injury to the nail can damage or break the bone underneath. A person should seek medical attention if:

  • the pain is unbearable
  • the injury has happened to a baby or child
  • the bleeding is uncontrollable
  • there is a cut or laceration
  • the base of the nail is damaged
  • any nail turns dark or discolored, with or without injury
  • there are signs of an infection, such as:
    • fluid or pus draining from under the nail
    • increased swelling or pain
    • red streaks in the skin
    • a fever
    • a feeling of heat or throbbing in the finger or toe
    • excessive redness around the area of injury

A doctor may need to remove a severely injured nail or use stitches for deep cuts.

Sometimes, the damaged nail can act as a cover to protect the nail bed while it heals. The damaged nail may need to be removed at a later date. When the damaged nail bed heals, the bleeding will stop and a new nail will grow.

Broken fingertips may require a splint to promote healing and to protect the area from further injury. They can take at least 6–8 weeks to heal.

Nail trephination

A doctor may perform a procedure called nail trephination to drain the blood from under the nail. This can help to relieve pain and pressure.

The doctor will make a small hole in the nail with a laser or needle. Afterward, the area may be wrapped with a bandage and may continue to drain for up to 3 days.

This procedure should not be attempted at home, as it can cause infections or further injury to the nail bed.

A minor subungual hematoma usually heals over time without treatment. The trapped blood will eventually be reabsorbed, and the dark mark will disappear.

This can take a number of months or years. Subungual hematomas heal more quickly when affecting the fingernail, while subungual hematomas on the toenails heal more slowly.

It takes around 6–9 months for the new nail to grow out. If there is severe damage to the nail bed, the nail may be malformed or cracked when it grows back. It may fail to regrow in some cases. Contacting a doctor for treatment when an injury occurs may help to prevent this.

Although it is rare, melanoma can occur under a fingernail or toenail. Melanoma is a type of skin cancer.

A tumor may look like a subungual hematoma. Melanoma can cause a dark mark to form under the nail. However, it does not usually cause pain and is not linked to an injury.

It is important to contact a doctor if a person has concerns about the appearance of blood under the nails, or if they have a subungual hematoma that does not heal.

Here are some frequently asked questions about subungual hematomas.

How long does a subungual hematoma take to heal?

A subungual hematoma may take months or years to heal on its own. The new nail may grow out within around 6–9 months, but this can differ for each person.

How do I know if my subungual hematoma is serious?

A subungual hematoma may be serious if the bleeding does not stop or if there is severe damage to the nail. A person should also seek medical attention if they experience a cut or laceration, or if there are also signs of infection.

How do you treat blood under your nails?

Depending on the cause, blood under the nails may slowly resolve on its own over time. A person can also take steps to encourage healing, such as resting the digit, using a cool pack, keeping the hand or foot elevated, and applying compression.

If bleeding is severe or accompanied by extreme physical trauma, it is important to contact a doctor for advice on medical treatments.

A subungual hematoma can affect fingernails and toenails. It happens when something causes the blood vessels under the nail to break open, with blood collecting and becoming trapped under the nail.

Possible causes of subungual hematomas include something falling on the nail or crushing it, stubbing the toe, wearing tight shoes, and repetitive stress with movements such as running.

Most cases of subungual hematoma will heal on their own within a number of months. Home remedies such as resting, icing, applying compression, and elevation can also encourage healing.

In more severe cases, medical treatments may be necessary. It is important to contact a doctor if a person experiences severe pain, bleeding that does not stop, signs of infection, or a subungual hematoma that does not go away on its own. They should also contact a doctor if it affects a baby or child.