Mouth swelling can happen in or around the mouth, such as the roof of the mouth, tongue, and lips. Causes range in severity, including temporary irritation from food or beverages to sudden swelling that may tighten the throat and restrict breathing. Read more below to learn about mouth swelling.

9 most common cause(s)

Herpes simplex virus

Canker Sore

Seasonal Allergies

Swollen mouth symptoms

The mouth is perhaps the most sensitive part of the body. If the mouth fails to detect you're eating something hazardous, this is potentially harmful. That's why your mouth responds right away with warning signals such as redness, pain, and swelling if it is touched by anything that might cause allergy or illness.

Common characteristics of a swollen mouth

If you're experiencing mouth swelling it can likely present with:

Swelling of the lips, tongue, and throat
Red, sore, blistered appearance on the inside of the mouth
A rounded lump anywhere inside the mouth: This lump may be painful or painless.
Difficulty speaking and with other mouth functions: Such as eating and swallowing due to dryness, pain, and swelling
Soreness and swelling of the roof of the mouth

Who is most often affected?

People who fit the following descriptions are more likely to experience a swollen mouth.

Anyone who smokes
Those not practicing good oral hygiene

Are swollen mouth symptoms serious?

The severity of mouth swelling depends on the cause.

Not serious: Temporary irritation from foods or beverages will heal quickly with a little care.
Moderately serious: See a physician for unexplained or persistent mouth swelling that causes pain or difficulty.
Serious: See a physician immediately for sudden swelling, throat tightening, and difficulty breathing.

What causes a swollen mouth?

Many conditions can cause the symptom of a swollen mouth. The following details may help you better understand your symptoms and when and if you need to see a physician.

Allergies

Allergies will usually cause swelling in other parts of the body, too, as well as in the mouth, lips, tongue, and palate (the roof of the mouth). If the reaction is severe, it can lead to anaphylaxis. Allergies can be due to the following.

Foods
Medications
Products for your oral health
Skincare products or makeup
Plants that you have touched just before touching your mouth
Insect bites or stings on the lips or even the tongue

Traumatic causes

Traumatic causes of tooth swelling may include the following.

Dental treatment or surgery: These procedures may cause swelling right after.
Sports injury: A ball or another player may strike you in the mouth and result in swelling.
Another injury: A car accident can cause trauma to the mouth.

Infectious causes

Infections of the tissues of and around the mouth itself can result in swelling.

Bacterial infection: A bacterial infection can cause an abscess, which is a painful, infected lump inside the mouth.
Cold sores: A viral infection or "cold sore" can cause the roof of the mouth to swell at the same time the sore appears.
Spreading tooth infection: In rare cases, bacteria may spread from a tooth infection and get into the floor of the mouth. This infection can cause enough swelling to displace the tongue and push it back until it blocks the throat and, though rare, can cause difficulty breathing and a medical emergency.
Ludwig's angina: A rare but serious infection of the space below the jaw and the floor of the mouth, under the tongue.
Herpetic stomatitis: A different virus caused by a herpes virus that mostly happens in children. It causes fever and red and inflamed gums.

Illnesses

Illnesses can lead to a swollen mouth, such as the following.

Viral illness: Some viral illnesses can cause swelling and itching of the roof of the mouth, along with a sore throat, swollen glands and tonsils, fatigue, and high fever.
Sinus infection: A sinus infection may cause swelling of the roof of the mouth as well as pain, pressure, fever, headache, and nasal congestion.
Blocked salivary gland: A blocked salivary gland can fill up with mucus and form a cyst. A cyst is a soft, painless swelling that will appear in the cheeks or on the floor of the mouth.
Angioedema causes swelling and puffiness of the face, mouth, tongue, hand, or genitals. It is often related to an allergic reaction to food, medicines, or insect bites.

Irritation

Redness, soreness, and swelling in the mouth can occur with repeated exposures to irritating substances such as the following.

Cigarette smoke
Chewing tobacco
Alcohol
Spicy foods
Rough, salty foods such as corn chips or jerky
Very hot beverages

Inflammatory causes

Inflammation of the mucosa, or tissues lining the mouth, can cause sores, redness, and swelling of the gums and mouth due to the following.

Gingivitis: An inflammation of the gums that’s caused by poor dental hygiene and the buildup of bacteria. Gums can become swollen, discolored, and bleed.
Radiation therapy to the head and neck
Chemotherapy
Oxygen therapy
Dehydration
Poor mouth hygiene
Alcohol and tobacco use
A very poor-quality, low-protein diet

Rare and unusual causes

More unusual causes of mouth swelling include the following.

Hereditary swelling: Some forms of swelling are hereditary and may involve the mouth and throat as well as other parts of the body (where the swelling is known as edema).
Tumors: These growths can cause swelling of the roof of the mouth if the tumor is above it or present as other types of mouth ulcers and lumps.

This list does not constitute medical advice and may not accurately represent what you have.

Cold sore

A cold sore is a skin lesion on the lips caused by infection with the herpes simplex virus (HSV). Cold sores are extremely common. In fact, most adults are infected with HSV, usually transmitted in childhood by normal close contact with parents, siblings or friends.

While the infection can be entirely unnoti..

Oral herpes

Herpetic stomatitis is a viral infection of the mouth that causes fever and red and inflamed gums. This typically happens early in childhood.

Rarity: Rare

Top Symptoms: fever, gum pain, painful mouth sore, gum swelling, gum redness

Symptoms that always occur with oral herpes: gum pain

Urgency: Self-treatment

Angioedema

Angioedema is a condition which can cause swelling and puffiness of the face, mouth, tongue, hand or genitals. It is often related to an allergic reaction to food, medicines or insect bites.

Rarity: Rare

Top Symptoms: nausea or vomiting, abdominal cramps (stomach cramps), diarrhea, swollen face, hand swelling

Urgency: Hospital emergency room

Swollen mouth treatments and relief

At-home treatments

You can try the following treatments at home.

Reduce or eliminate tobacco use: Take steps to stop smoking and to stop using any chewing tobacco products.
Cut down or discontinue drinking alcohol
Practice good oral hygiene: Floss regularly and brush your teeth and gums at least twice per day.
Protect your face: Use approved mouth guards and face masks when playing sports that require them.

Here are some over-the-counter treatments that might help:

Oral Antihistamines: Useful if your swelling is due to allergies. Check out options like Benadryl or Claritin.
Pain Relievers: Ibuprofen or acetaminophen can help manage discomfort associated with swelling.
Mouthwashes: Antiseptic options can aid in reducing irritation and infection, ensuring good oral hygiene.

When to see a doctor

You should consult your physician for any unexplained or troublesome lump or swelling, especially if you have pain, fever, or the feeling that the throat is constricted.

When it is an emergency

Seek immediate swollen mouth treatment in the emergency room or call 911 if you experience the following, which are symptoms of anaphylaxis, a severe allergic reaction that can be life-threatening.

You have a swollen mouth and face with difficulty breathing
Rapid heartbeat
A rash
A feeling of panic

Questions your doctor may ask about swollen mouth

What part of your mouth is swollen?
Do you have a rash?
Does your throat feel itchy or irritated?
Are your symptoms worse while eating?

Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.

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The stories shared below are not written by Buoy employees. Buoy does not endorse any of the information in these stories. Whenever you have questions or concerns about a medical condition, you should always contact your doctor or a healthcare provider.

Jeffrey M. Rothschild, MD, MPH.

Associate Professor of Medicine, Brigham and Women’s Hospital

Dr. Rothschild has been a faculty member at Brigham and Women’s Hospital where he is an Associate Professor of Medicine at Harvard Medical School. He currently practices as a hospitalist at Newton Wellesley Hospital. In 1978, Dr. Rothschild received his MD at the Medical College of Wisconsin and trained in internal medicine followed by a fellowship in critical care medicine. He also received an MP...

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