Often, a person can take care of a deep cut inside the lower lip with first aid. If significant bleeding continues after applying pressure, then swift medical care may be necessary.

Cuts inside the mouth heal faster than cuts elsewhere. They can still become infected, though, so getting the right medical care is important.

In this article, we look at the symptoms of a deep cut inside the lip, how to perform first aid, and when to see a doctor.

A woman looking in a mirror at her lip, to accompany an article on what to do for a deep cut inside the lower lip.Share on Pinterest
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Cuts inside the lips typically bleed a lot and cause pain. Because of the blood, it can be hard to see how deep a cut is.

Shallow cuts usually heal on their own without stitches, while deep cuts may require medical attention.

Stitches may be necessary if the wound:

If there is so much blood that seeing the wound is not possible, apply pressure with a cloth, keep it held down, and seek medical attention.

Also, seek medical attention if the cut:

  • looks dirty
  • was caused by an animal bite
  • was caused by a puncture with a dirty object
  • is extremely painful
  • could have damaged other parts of the mouth or face

If a cut is not new but has any of the characteristics above, contact a doctor as soon as possible.

Cuts in the mouth can become infected, and symptoms include:

  • swelling
  • pus
  • a fever

A doctor may treat the infection with antibiotics.

Whether a person is waiting for medical treatment or caring for an oral injury at home, first aid can help stem the flow of blood and reduce the risk of infection.

To perform first aid on a deep cut in the mouth:

  1. Wash the hands thoroughly.
  2. Apply pressure with a clean cloth or bandage for several minutes.
  3. Once the bleeding slows or stops, rinse the mouth with cool water to remove any particles from the wound.
  4. Try sucking on an ice cube to limit further bleeding and swelling.

If the bleeding does not slow or stop after 5–10 minutes, the person may need professional care.

How doctors treat a deep cut inside the lip will depend on the location and severity of the wound. But they usually begin by cleaning the wound with sterile water or saline and assessing the injury.

Depending on the cause of the cut, the doctor may:

  • Administer a local anesthetic so that they can inspect the wound more closely without causing pain.
  • Order medical imaging tests to look for foreign objects that may be stuck in the wound.
  • Prescribe antibiotics if there is a possibility of infection.
  • Order a tetanus shot for a puncture wound, if the person has not had a tetanus booster in the last 5 years.

The doctor may then seal the wound with stitches. They may also provide an antibiotic ointment to help the person keep the wound clean at home.

After receiving medical care, keeping the cut clean gives it the best chance of healing.

The doctor will have provided specific advice, but aftercare may involve taking oral antibiotics or applying an antibiotic product, such as an ointment, to the cut.

The person may also need pain relief medication, anti-inflammatory drugs, or both. Versions of these are available over the counter. If the cut is making eating difficult, stick to softer foods until the pain improves.

If the person has stitches, a doctor may need to remove them later on, depending on the type of thread material, or suture, involved.

Healing times can vary — but cuts inside the mouth tend to heal faster than those elsewhere. A 2018 study found that saliva helps with healing because it contains proteins that promote tissue repair.

Also, as the authors of research from 2013 explain, wounds heal quicker inside the mouth because of the humid environment. And cells in the oral cavity reproduce faster than those elsewhere, speeding up the healing process.

Complications of an injury to the inner lower lip include infection and scarring. Practicing first aid and keeping the wound clean can help prevent infection, but this remains a risk until the wound has fully healed.

It is important to follow a doctor’s guidance and to notify them if the wound seems infected or the person develops a fever.

While many injuries are unavoidable, a person can take a few steps to prevent serious cuts inside the mouth.

Stanford Children’s Health recommend:

  • not walking or running with objects inside the mouth
  • not biting or chewing on sharp objects, such as pencils
  • wearing oral protective gear while playing sports

Also, chewing food slowly and not multitasking during mealtimes may reduce the risk of biting the inner lips or cheeks by accident.

Cuts inside the mouth can bleed a lot, but they do not always need stitches. Shallow cuts often heal on their own, and first aid at home can stem the bleeding and reduce the risk of infection.

However, if a cut is large, deep, or ragged, or if significant bleeding continues after the person has applied pressure for 5–10 minutes, swift medical care may be necessary.

A doctor can treat a deep cut inside the lip and take steps to prevent infection. If necessary, they can administer stitches.

The doctor may also prescribe antibiotics or give a tetanus shot if there is a risk of infection.

If the cut looks infected or was caused by an animal, seek professional treatment right away.