You may bite your tongue in your sleep due to underlying causes, such as facial muscle spasms, seizures, and Lyme disease, among others. Treating these can help you stop biting your tongue.

You won’t feel like saying anything except for “ouch” after biting your tongue. While there are no statistics on how many people bite their tongues, experts say it happens to everyone from time to time.

However, tongue biting is also common during sleep. Seizures and any condition causing facial muscle spasms may result in tongue biting at night.

People who bite their tongues are at risk of developing ulcers, infections, and a condition called “scalloping” on their tongues. So it’s important to seek treatment if you find you’re biting your tongue.

There are several reasons why you might bite your tongue in your sleep. When a person bites their tongue in the daytime, they’re most likely conscious. However, you’re more likely to bite your tongue unconsciously at night. In most cases, an underlying medical condition leads to tongue biting during sleep.


Bruxism, or teeth grinding and clenching, is a common movement problem that can affect you during sleep. It most often affects the teeth and jaws, causing soreness, pain, and injury. But bruxism can also cause a person to bite their tongue and cheeks. Doctors aren’t sure exactly what causes bruxism, but think it has something to do with dreaming or perhaps being aroused during sleep.

Facial muscle spasms

Facial and jaw muscle spasms can cause tongue biting during the night. This condition is most commonly seen in children, and often causes the chin to tremble uncontrollably during sleep.

People who experience these spasms are unable to control their facial and jaw muscles during sleep, and often bite their tongues. This condition is also called “faciomandibular myoclonus.”

Illicit drug use

MDMA, also known as “molly” and ecstasy, is an illicit drug that causes extreme euphoria. It also appears to cause bruxism, which can cause severe injury to the teeth, cheeks, and tongue.

While experts aren’t exactly sure what causes bruxism in people who have taken MDMA, some think MDMA may intensify the desire to bite or chew. Research on rats suggests MDMA may lead to a reduced ability to keep the jaws open.

Lyme disease

Lyme disease is not a very well-understood illness. But it appears to cause issues with the central nervous system and bodily reflexes. This may cause you to accidentally bite your tongue or cheeks. Other signs of Lyme disease include:

  • abnormal sensitivities to heat and cold
  • fatigue
  • slurred speech
  • frequent diarrhea
  • vision changes
  • generalized pain and tingling

Nighttime seizures

Nighttime seizures are a common cause of tongue biting. Those with epilepsy lose control of their bodies during a seizure. This may cause them to unconsciously bite down on their tongue. Usually, bites occur on the tip and sides of the tongue. About 50 million people worldwide have epilepsy.

Rhythmic movement disorder

Rhythmic movement disorder strikes while a person is drowsy or asleep. It causes a person to repeat body movements over and over again. Mostly children are affected by this condition. It may cause them to produce humming sounds, body motions like rocking and head banging, or rolling. These movements may be rapid and may cause tongue biting.

Sleep apnea

Sleep apnea does not cause tongue biting, but tongue biting is common in many people with sleep apnea. This is because people with sleep apnea often have tongues that are especially large or muscles in the mouth that relax abnormally during sleep.

Relaxed muscles and a large tongue can lead to tongue biting. Other signs of sleep apnea include:

  • loud snoring
  • gasping for air during sleep
  • morning headache
  • excessive daytime sleepiness

It’s not always easy to determine that you’ve been biting your tongue when you sleep. However, there are some signs that can make nighttime tongue biting easier to identify. These include:

  • tongue bleeding
  • redness or swelling of the tongue
  • pain
  • cuts or marks on the tongue
  • ulcer on the tongue
  • raw, scalloped edges on the tongue

Treatment for tongue biting involves treating the underlying condition.

Those suffering from sleep bruxism or sleep apnea may benefit from wearing a mouthguard at night. Talk to a dentist or doctor about which are best for your condition. Sleep apnea can also be treated with:

If illicit drug use is causing you to bite your tongue during sleep, stopping use of the drug is usually enough to stop symptoms. If you need help giving up the drugs or are still experiencing health problems after stopping, see a doctor.

Nighttime seizures caused by epilepsy are best treated with antiseizure medication. Those experiencing muscle spasms in their face and jaw at night may also benefit from antiseizure medication, according to researchers.

Most children grow out of rhythmic movement disorder. However, if your child has injured themselves during sleep, you should speak to their pediatrician.

Those with Lyme disease should stick to their doctor’s treatment plan. Usually this involves a mix of antibiotic and supportive therapies that help reduce symptoms.

Tongue injuries usually heal quickly without any medical intervention. However, if you notice an ulcer, redness, excessive bleeding, pus, or lacerations, you should seek medical attention.

If you’ve experienced tongue biting during sleep in the past, there are some things you can do to prevent it from happening in the future.

Sleep study

As mentioned above, to treat tongue biting you need to treat any underlying conditions that are causing the problem. Asking a doctor to recommend a specialist who can do a sleep study is one way to get to the bottom of your problem.

This involves spending one to two nights in a sleep facility. There, a sleep expert will record some of your body functions with electrodes and monitors.

The recordings of your brainwave activity, eye movement, muscle tone, heart rhythm and breathing rate may help your doctor determine what’s causing you to bite your tongue. They can then recommend a treatment that’s appropriate for you.


For many people who bite their tongue, wearing a mouthguard can prevent future injuries. Because everyone’s mouth is different, talk to a dentist or doctor about which type of mouthguard is best for you. You may want to get a customized mouthguard that perfectly fits your teeth. Or, you may choose to purchase a less expensive, non-customized version.

Reduce stress

One major cause of nighttime bruxism that leads to tongue biting is stress. To reduce your risk of tongue biting, you should focus on reducing your stress during the day. If you find yourself feeling less calm than you would like, perhaps try some relaxation techniques like deep breathing, meditation, or yoga.

Don’t use illegal drugs

Avoid illicit drugs, including MDMA, which increase your risk of bruxism. The higher the dose and frequency of your MDMA use, the more likely you are to experience the negative side effects.


If you’re on antiseizure medications, making sure to take your drugs as prescribed can help prevent seizures and tongue biting. If you’re finding that you still experience seizures or tongue biting while on medication, talk to your doctor about adjusting your dose.

Everyone bites their tongue from time to time. However, those who bite their tongues frequently during sleep often have underlying medical conditions that should be treated to reduce symptoms. Treating tongue biting involves addressing any existing conditions, such as sleep apnea and epilepsy.

If you’re not sure what’s causing your tongue biting, it can help to take part in a sleep study. Talk to a doctor about how to get one and how it may benefit your sleep.