What to Do About Blood Under Your Nail

Sometimes hand or foot injuries result in bleeding under the nail, a condition called subungual hematoma. These bleeds can result in darkened discoloration, such as black spots, and pressure and pain. They can usually be resolved with ice and elevation at home, but talk to a healthcare provider if you experience severe pain or impaired movement that suggests a possible fracture or other complication.

How to Treat a Subungual Hematoma

If the subungual hematoma is small, you might not need medical care. You can try:

• Resting your finger
• Applying ice wrapped in a towel on your finger
• Elevating your finger
• Taking over-the-counter pain medication like ibuprofen

Nail trephination

Nail trephination uses hot metal wire, an electrocautery device, or a spinning, large-bore needle to pierce the nail plate for drainage. The nail plate has no nerves, so this process is painless. 

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.

What to Do After Treatment

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 your nail is removed, the wound should heal in a few weeks, but it may take about six months for the nail to grow back. Follow your healthcare provider’s instructions for nail care. 

For general nail care:

• Elevate your injured nail
• Avoid getting it wet: Cover it with a plastic bag when showering
• Removing the bandage after two days: Gently wash around the wound twice daily, then apply vaseline and a nonstick bandage  

Common Causes of Blood Under Your Nail

Subungual hematomas often result from injury, such as stubbing your toe, hitting your finger with a hammer, or slamming it in a car trunk.

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