What to Do When You Have Dried Blood Under Your Fingernail

Also called subungual hematoma

Updated on May 04, 2023

Medically reviewed by Adam H. Kaplan, DPM

Dried blood under the fingernail can happen when an injury causes bleeding under the nail. This is medically known as subungual hematoma. These bleeds can result in darkened discoloration, such as black spots, and pressure and pain.

This article will explore the treatment options for a subungual hematoma.

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Treatment

If the subungual hematoma is small, you may not need to seek medical care. You can treat it by:

Resting your finger
Wrapping ice in a towel and putting it on your finger
Elevating your finger
Taking over-the-counter pain medication like ibuprofen

When to See a Healthcare Provider

If the affected area continues to collect blood, you're experiencing extreme pain, or the injury is at the base of the nail, it's best to see a healthcare provider. Also see your healthcare provider if you have other symptoms like swelling or inability to move the finger or toe. You might have a fracture. If it is continuing to bleed, you may have a laceration which requires sutures. It takes about 48 hours for blood at the level of the nail bed to clot. If you wait longer than 48 hours to see a healthcare provider, drainage may not be possible.

Nail trephination

Nail trephination uses hot metal wire, an electrocautery device, or a spinning, large-bore needle to pierce the nail plate for drainage.

Fortunately, the nail plate lacks nerves, so this process doesn't hurt.

The hole created by piercing should be large enough to let the blood drain. This takes about a day or two. During this time, the hole through which the blood oozes should be covered with sterile gauze. This procedure can help prevent a situation in which the nail needs to be removed or where the nail falls off by itself.

Removing the Nail

If the hematoma covers more than half the nail or the nail injury is deep, your healthcare provider may choose to remove the nail completely.

Before removing the nail, your healthcare provider will numb the area, which is called a digital block, so that it doesn't hurt to have it taken off.

Keep in mind that it can take several months for a nail to grow back.

Recovery

After a nail trephination, make sure to follow all instructions from your healthcare provider, including methods of pain relief and caring for the finger or toe. Your healthcare provider may recommend:

Soaking your finger or toe for 15 minutes a day in a warm solution with Epsom salts to help drain fluid and alleviate pain
Taking an over-the-counter pain reliever like ibuprofen (you shouldn't need an oral antibiotic)
Elevating the affected toe or finger
Using a cool compress
Applying an antibiotic ointment to the area with each dressing change

If you have to get your nail removed, the wound should heal within a few weeks but it may take about six months for your nail to grow back. Follow your healthcare provider's instructions for how to care for your injured nail.

Some general advice for caring for your injured nail includes:

Elevating it
Not getting the nail wet (cover it with a plastic bag when you shower)
Removing the bandage after two days and gently washing around the wound twice a day, then covering it with vaseline and a nonstick bandage

Complications of Subungual Hematoma

If damage to your nail is extensive, there's a small chance that your nail matrix may have been damaged. The nail matrix is where your fingernails and toenails form. Damage to the nail matrix may mean that your nail may not grow back or that your nail may look different when it grows.

Causes

A subungual hematoma is usually caused by a traumatic injury. Examples include stubbing your toe, hitting your finger with a hammer, or slamming your finger in a car trunk.

You may also experience bleeding under your toenail if you wear shoes that are too tight.

When to See Your Healthcare Provider

If you experience bleeding under your nail, see your healthcare provider as soon as possible. If it's been less than 48 hours, your healthcare provider or urgent care physician can drain the excess fluid and relieve the pressure.

Also see your healthcare provider if you have other symptoms like swelling or inability to move the finger or toe. You might have a fracture. If it is continuing to bleed, you may have a laceration which requires sutures.

Summary

Subungual hematoma, or bleeding under the nail, can cause discoloration, pressure, and pain.

If you see your healthcare provider within 48 hours, it can be drained to relieve pressure.

If you have other symptoms suggesting a fracture, you experience pain, or the discoloration appears without a known cause, always see your healthcare provider.

5 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

American Osteopathic College of Dermatology. Subungual hematoma.
American Osteopathic College of Dermatology. Subungual hematoma.
Bansal A, Choudhary P, Relhan V. Traumatic nail disorders. In: Grover C, ed. Textbook of Onychology. Evangel Publications; 2020:430-447.
Briggs B. Clinical controversies: Bye-bye, fingernail? Not so fast. Emerg Med News. 2021;43(9):20. doi:10.1097/01.EEM.0000791956.55664.c8
Kaiser Permanente. Toenail or fingernail avulsion: Care instructions.