What Causes Foaming at the Mouth?

Foaming at the mouth happens when excess fluid in your mouth or lungs mixes with air, causing froth to appear. This symptom can be caused by several serious health conditions.

What does white foamy saliva mean?

Unexpected froth or foam coming from your mouth is a rare and serious symptom. If you see it, you should call 911 or your local emergency services and get emergency medical assistance right away.

Some health conditions can interrupt a person’s ability to swallow, causing saliva to pool in the mouth and become foamy. In other cases, excess fluid in the lungs can mix with air and create foam that comes out of the mouth.

This article looks at four conditions that can cause foaming at the mouth.

Opioids are substances that relieve severe pain. They work by acting on specific receptors in your brain and nerves.

Almost two-thirds of that $3.3 trillion cost – 64% – is paid for by American tax dollars, and that amount is growing. A study by the American Journal of Public Health predicts that taxpayers will shoulder 67.3% of the burden of healthcare costs by the year 2024, Physicians for a National Health Program

Opioid toxicity or overdose is a medical emergency. It happens when opioids stop your body from being able to breathe. This can result in foaming at the mouth.

Overdose can happen in situations such as:

taking too much of a prescription opioid medication or drug
taking substances that have been laced with fentanyl without your knowledge
mixing opioids with other substances such as alcohol or benzodiazepines

Prescription opioid medications include:

Prescription opioids are mainly used to treat pain that doesn’t respond to other medications. These medications are important for managing serious pain, but they’re known to have many side effects, including the risk of developing a tolerance to or dependence on opioids.

Opioids are also found in the illegal drug supply. Some opioids, such as heroin, are only available illegally. Others, like fentanyl, are used in specific healthcare contexts but are also produced and sold illegally.

Many drugs sold illegally are laced with the opioid fentanyl, which can lead to an unexpected opioid overdose.

Opioid overdose symptoms

Opioid overdose can cause foaming at the mouth because the overdose affects your lungs. When breathing stops or slows, fluid gathers in your lungs. This fluid can mix with air and come out of the mouth like a foam.

Common symptoms of opioid overdose include:

small pupils
loss of consciousness
weak, slow, or stopped breathing
gurgling or choking
seizures
limpness
cold or clammy skin
discolored or blue lips or nails

What to do if someone is having an opioid overdose

If you suspect someone is having an opioid overdose, call 911 or your local emergency services. A medication called Narcan (naloxone) can help reverse opioid overdoes.

Naloxone can save lives

Naloxone, also known as Narcan, is a medication that helps reverse opioid overdose. If someone in your life may be at increased risk of opioid overdose, the Centers for Disease Control and Prevention (CDC) recommends keeping naloxone on hand.

Many pharmacies and community programs distribute naloxone. In many states, no prescription is necessary to get naloxone, and there may be free or low cost options to get naloxone in your area.

In addition, many public health departments and harm reduction programs offer naloxone training. This training teaches you when and how to administer naloxone.

Resources such as Next Distro provide information on naloxone access in every state and can ship naloxone by mail.

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Historically, people associated all seizures with foaming at the mouth. In fact, there are many different types of seizures, and only some types cause this symptom.

A tonic-clonic seizure is the type most often associated with mouth foaming. This type of seizure is often caused by a brain condition called epilepsy.

However, tonic-clonic seizures can also be brought on by fever, low blood sugar, a head injury, or other conditions.

A seizure that’s caused by a fever is called a febrile seizure. This type affects young children more often than adults.

Febrile seizure is fairly common, affecting up to 4% of children between the ages of 6 months to 5 years. If a fever causes a tonic-clonic seizure, this can lead to foaming at the mouth.

Seizure symptoms

Symptoms of tonic-clonic seizure include:

a headache or strange feeling before the seizure, known as prodrome
crying out
stiffening of the body
turning pale or blue
falling
eyes rolling back into the head
losing consciousness
frothing at the mouth or drooling
convulsions, or jerking of the arms and legs
temporary loss of bladder control

What to do if someone is having a seizure

If someone appears to be having a seizure:

Help ease them to the ground if needed.
Put a soft flat object under the person’s head for cushioning.
Do not move the person having a seizure unless it is absolutely necessary. Instead, move sharp or potentially dangerous objects out of the way.
Remove eyeglasses and loosen tight clothing around the neck.
Do not put anything in the person’s mouth or offer food or water.
When jerking movements stop, gently turn the person to their side.
Keep track of how long the seizure lasts.
Stay with the person until they are fully awake.

Febrile seizures usually don’t cause lasting effects for a child, but it is important to contact a doctor when a seizure occurs.

Some people with known seizure conditions have a care plan in place and may not need emergency care. Talk with the person to explain what has happened.

Rabies symptoms

Foaming at the mouth is one of the most characteristic symptoms of rabies. This happens because the virus affects the nervous system, making swallowing difficult.

Often, the first symptoms of a rabies infection include itching or tingling around the bite and flu-like symptoms such as:

When symptoms progress, a person or animal may begin to foam at the mouth. Other advanced symptoms include:

agitation or difficulty staying still
aggression
hallucinations
muscle spasms
seizure
paralysis
extreme weakness
difficulty swallowing

How does rabies spread?

The rabies virus is found in the saliva of infected animals. The condition can also be spread by saliva from an infected animal getting into your eyes, nose, mouth, or a scrape or wound on your body. An infected animal may not have any visible symptoms.

Which animals carry rabies?

Many animals can carry rabies. In the United States, some common carriers of the rabies virus include:

Raccoons often carry the rabies virus. However, according to CDC data, bats are the most common cause of rabies exposure in the United States.

If you come into direct contact with a bat, or wake up and find a bat in your room, you should call 911 or your local emergency services or go to the emergency room. If a bat bites or scratches you, the wound may be too small to see.

In the United States, most pet dogs are vaccinated against rabies. But if you’ve been bitten by a dog and don’t know the dog’s vaccination history, it’s important to get emergency care to prevent rabies.

If an animal bites you, or you come into contact with an animal that could be carrying rabies, it’s important to get checked out by a doctor right away. You can avoid potential infections or complications by getting prompt medical care.

What to do you if you may have been exposed to rabies

If you’ve been bitten by an animal or you think you’ve been exposed to rabies, call 911 or your local emergency services or go to the nearest emergency department.

Clean your wound well with soap and water and cover it with a bandage. At the hospital, a doctor will help determine whether you need treatment to prevent rabies.

The rabies vaccine stops the rabies virus from causing an infection. Once symptoms start, there is no way to treat rabies, and the infection is usually fatal.

Symptoms of poisoning

Foaming at the mouth can be a symptom of poisoning. Other possible symptoms can include:

drooling
difficulty breathing
dry mouth
vomiting or diarrhea
a rash on your skin or around your mouth
pupils that are very large or very small
fainting
shaking
confusion
seizure

To prevent accidental poisoning, it’s important to follow instructions on household products and medications and to store these items safely out of the reach of children.

What to do if a person may have been poisoned

Poisoning can be very serious and even life threatening. Depending on the cause and symptoms, emergency care may be needed.

If you think someone has been poisoned and they are alert and awake, call the National Poison Control Centers at 800-222-1222.

If the person is unconscious, having trouble breathing, or has other serious symptoms, get emergency medical help by calling 911 or your local emergency number.

The causes of foaming at the mouth are very specific and require unique treatment methods:

An opioid overdose can be treated with naloxone and emergency medical care.
Tonic-clonic seizures can be treated with antiepileptic medications, surgery, or other medical care, depending on the cause.
Rabies can be prevented with a series of vaccines.
Poisoning may require hospital treatment, depending on the cause, level of exposure, and symptoms.

Foaming at the mouth can be a symptom of a serious medical condition.

If you experience foaming at the mouth, or see someone with frothy saliva, get emergency medical help immediately.

A person who routinely has seizures may have a care plan in place and may not need hospital care every time they have a seizure. But if you’re unsure, it’s better to err on the side of caution and call for help.

Last medically reviewed on March 28, 2023