How to Treat a Smashed Finger

What to Do and What Not to Do

The very mention of a finger getting crushed in a door or pounded by a hammer is enough to make people cringe. A smashed finger is not only unpleasant and uncomfortable, but it may be serious enough to require an emergency room visit.

This article walks you through the first aid steps if you or someone you know has a smashed finger. This includes knowing what not to do and when it's time to see a doctor.

How to Treat a Smashed Finger


Immediate First Aid

The first step in treating a smashed finger is to manage the pain and swelling. There are four ways to do this:

  1. Ice it. An ice pack can quickly reduce pain and swelling. Apply ice for 15 minutes at a time, a couple of times an hour for the first few hours. Don't ice the finger for more than 15 minutes or you may get frostbite.
  2. Elevate it. Raising the injured finger above the heart slows the blood flow and reduces the throbbing. Letting your hand dangle will increase the pain and swelling.
  3. Use it. If possible, keep using the finger to promote circulation. If you can't move it or begin to lose sensation in the finger, call your doctor.
  4. Take a pain reliever. Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) like Advil (ibuprofen) can help reduce pain and swelling. Tylenol (acetaminophen) is also good at relieving pain.

Treating Blood Under a Fingernail

When a finger is smashed, blood can pool beneath the fingernail, leading to what is called a subungual hematoma. After a day or two, the nail may start to turn blue or even black. Doctors may consider draining the blood if it is causing pain but will otherwise leave it alone.

Doctors generally advise against draining the nail yourself as you can injure yourself or cause an infection by introducing bacteria into the nail bed. In more cases than not, the nail will look worse than it actually is and will benefit from being left alone.

If the pressure beneath the nail is causing excessive pain, your doctor may give you the OK to drain the blood yourself. Doing so requires four things: a lighter, a pair of pliers, a clean paper clip, and a clean paper towel.

Here's how to do it:

  1. Wash the finger thoroughly with soap and water.
  2. Open the paper clip so that you have a straight edge.
  3. Holding the paper clip with the pliers, heat the tip in the flame until it is red hot.
  4. Carefully touch the red-hot tip to the part of the nail where the most blood has collected.
  5. Place gentle pressure and allow the heat of the paper clip to burn through the nail plate. Do not push.
  6. As the paper clip penetrates the nail, there may be a gush of blood. Remove the paper clip and grab the paper towel to wipe away any excess blood.

This can be repeated as needed but should only be done if there is pain. This should not be performed for cosmetic reasons.

If your nail eventually falls off, don't panic. It's not ideal, but chances are good that it will grow back.


You should not try to drain blood from under a fingernail unless it is to relieve pain and your doctor gives you the OK.

What Not to Do

There are two things you should not do if you have a smashed finger:

  • Do not wrap a smashed finger. Doing so can reduce the blood flow and, in turn, the oxygen and nutrients the finger needs to heal itself.
  • Do not splint a smashed finger, Splinting may be useful if there's a break but can also affect blood circulation. Don't do it without first speaking with a doctor.

When to See a Doctor

In most cases, a smashed finger won't require a doctor's visit. With that said, it may be necessary if the injury is severe or there are signs of a fracture or infection.

You should see a doctor if:

  • The finger is bent and cannot be straightened.
  • The skin is broken and you can see bone.
  • The injury involves the palm or any joint (such as the wrist or a finger).
  • There is significant numbness or loss of sensation.
  • The pain is exceptionally severe.
  • There is increasing swelling, pain, redness, pus-like discharge, or other signs of infection.


If you smash a finger, the first step is to relieve the swelling and pain with an ice pack, elevation, and an over-the-counter painkiller if needed. Moving the finger helps promote circulation. If there is blood beneath the fingernail, do not drain it yourself unless your doctor gives you the OK.

Unless your doctor says otherwise, never splint or wrap a smashed finger as this can impede blood flow. While most smashed fingers don't require a doctor's visit, you should do so if there are signs of an infection or a severe injury.

Frequently Asked Questions

  • How long does the pain last when you smash your finger?

    Depending on the extent of the injury, the pain may last for a few days or a few weeks. Draining the blood from under the fingernail may help if the pain is severe, but do not do this yourself without your doctor's OK.

  • How long does a smashed finger stay swollen?

    This can vary, but the swelling generally goes down quickly if you treat it with an ice pack and an over-the-counter nonsteroidal anti-inflammatory drug (NSAID) like Advil. Most of the acute swelling will go down in a few days, but mild swelling may persist for several weeks.

6 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.
  1. Cheung K, Hatchell A, Thoma A. Approach to traumatic hand injuries for primary care physicians. Can Fam Physician. 2013 Jun;59(6):614-8.

  2. MedlinePlus. Smashed finger. Updated November 30, 2021.

  3. Hung KKC, Graham CA, Lo RSL, et al. Oral paracetamol and/or ibuprofen for treating pain after soft tissue injuries: Single centre double-blind, randomised controlled clinical trial. PLoS ONE. 2018;13(2):e0192043. doi:10.1371/journal.pone.0192043

  4. American Osteopathic College of Dermatology. Subungual hematoma. Updated 2020.

  5. Won SH, Lee S, Chung CY, et al. Buddy taping: is it a safe method for treatment of finger and toe injuries? Clin Orthop Surg. 2014;6(1):26-31. doi:10.4055/cios.2014.6.1.26

  6. Mount Sinai. Smashed fingers. Updated June 3, 2021.