- Signs and Symptoms
- When to See a Doctor
What is a mouth blister?
A mouth blister is a sore on the lips, cheeks, tongue, or other soft areas inside or around the mouth. Everything from dental work to an accidental bite while eating can cause these uncomfortable blisters.
Many types of mouth sores will go away on their own, but some may require medical attention.
Signs and symptoms of mouth blisters
Mouth blisters can look different depending on their cause and where they appear. Generally, they appear as white- or yellow-capped sores or rashes anywhere on the surface of your lips, the insides of your cheeks, the tongue, or the gums. It can be painful to eat, drink, speak, or swallow while you have a mouth blister.
Types of mouth blisters
The following are different types of mouth blisters:
Canker sores, also known as mouth ulcers, usually appear inside the lips, but they can also appear on the tongue, cheeks, and gums. They are usually under a half-inch long, are white or yellowish, and are oval-shaped, often with a red ring around them and slightly raised. Left alone, minor canker sores usually heal within a week.
Cold sores, also known as oral herpes, appear outside of the mouth on the surface of the lips or the skin surrounding them. Caused by a virus, they are usually small with a white or yellowish surface and can form in patches of several at once. They begin with a tingling, burning, or itching sensation for a day or two, then grow into blisters.
Symptoms such as muscle aches, fatigue, headache, and fever can accompany a cold sore’s first appearance. Once the blisters pop, they scab over and heal without scarring in two to three weeks, but they can reappear later. Cold sores are highly contagious.
Transient lingual papillitis
Also known as tongue or “lie” bumps, these are small, inflamed sores on the top or sides of the tongue. Usually very small, these blisters can have a red or white surface and occur when taste buds (papillae) become irritated. They can be painful, but they heal on their own within a few days after appearing.
Sometimes referred to as thrush, this type of mouth blister is a white or light-colored rash that appears in patches on the tongue or other areas inside the mouth. This infection can cause burning sensations or soreness in the mouth or throat, along with bad breath. Thrush can sometimes heal on its own but may need medical treatment.
Causes of mouth blisters
Blisters in the mouth can have a variety of causes:
External irritation or injuries commonly cause canker sores and other mouth blisters. Accidentally biting your lips, as well as allergies, dental work, and certain toothpastes and mouthwashes, can lead to canker sores.
Viruses and infections
A common cause of cold sores and other blisters outside and inside of the mouth is the herpes simplex virus. This infection can spread through kissing, oral sex, or sharing eating utensils and other objects that touch the mouth. Herpes usually isn’t serious, but it can cause complications for people with weakened immune systems from medication or pre-existing illnesses.
Infections and viruses can also lead to thrush. The fungus that causes thrush, Candida, naturally lives in our mouths in small amounts. Our immune system is meant to keep this fungus under control. However, in older adults, very young children, and others with reduced immunity, the fungus can overrun the mouth and create a thrush rash.
Early symptoms of mouth cancer include sores and other unusual marks or rashes inside the mouth. A sign of mouth cancer is bright red, white, or grey patches on the cheeks, under the tongue, and behind the back teeth. Generally, cancerous sores last beyond two weeks, unlike most canker sores and other mouth blisters.
When to see the doctor for mouth blisters
If your mouth blisters do not resolve on their own within a few weeks or recur even with over-the-counter treatments, contact your doctor. The blisters could be a symptom of an underlying condition that needs attention.
Diagnosis and tests for mouth blisters
Canker sores and other mild blisters in the mouth don’t require a medical test or diagnosis for over-the-counter treatment. If you’re concerned that they may stem from a larger issue, a doctor can perform tests to diagnose any underlying cause of the blisters, including a blood test or a biopsy.
Treatments for mouth blisters
Leave the mouth blister alone. Don’t bite, pick, or otherwise irritate it — this can lead to infections and/or permanent scarring. Holding ice to a canker sore can reduce swelling.
At the drugstore, look for products containing the active ingredient benzocaine, which is a topical anesthetic. If you’re unsure of what products to use, or if what you’re using has not been effective, contact your doctor.
American Academy of Dermatology Association: "Herpes simplex: Who Gets and Causes."
Boston Children’s Hospital: "Testing & Diagnosis for Canker Sores (Aphthous Stomatitis) in Children."
Cedars-Sinai: "Everything You Ever Wanted to Know About Canker Sores."
Centers for Disease Control and Prevention: "Candida infections of the mouth, throat, and esophagus."
DermNet NZ: "Transient lingual papillitis."
InformedHealth: "Canker sores (mouth ulcers): Overview."
Journal of Clinical Dentistry: "Duration and Intensity of Anesthetic Effect Produced by Canker Sore Medications."
Medical News Today: "Oral thrush: All you need to know."
National Institute of Dental and Craniofacial Research: "Detecting Oral Cancer: A Guide for Health Care Professionals."
Postgraduate Medicine: "Canker sores."
The Laryngoscope: "Diagnosis and management of long-standing benign oral ulceration."
Top What Are Causes of Blisters in the Mouth Related Articles
Are Cold Sores (Fever Blisters) Contagious?About 20% of cases of cold sores are caused by herpes simplex virus type 2 (HSV-2), and approximately 80% of cold sores are caused by herpes simplex virus type 1 (HSV-1). Cold sores are transmitted by sharing utensils and razors, kissing, and oral sex. There is no cure for cold sores.
benzyl alcoholBenzyl alcohol is a component of creams and ointments applied topically to relieve pain from cold (canker) sores or blisters in the mouth and gum irritations, and to treat head lice infestation (pediculosis). Common side effects of benzyl alcohol include itching (pruritus), redness (erythema), application site reactions, pain, irritation, reduced sensation (hypoesthesia), loss of sensation (anesthesia), eye irritation, dry skin (xeroderma), skin rash, skin peeling (desquamation), skin picking (excoriation), tingling and numbness (paresthesia), dermatitis, seborrheic dermatitis of scalp, and burn (thermal) injury.
Canker SoresCanker sores are a common complaint, and are small ulcers on the inside of the mouth. Canker sores aren't contagious (as opposed to cold sores), and typically last for 10-14 days usually healing without scarring. A variety of things cause canker sores, for example, medications (aspirin, beta-blockers, NSAIDs, high blood pressure medication, and antibiotics); injury to the mouth from dental work, braces, or sports accidents; acidic foods; allergies; and diseases or conditions like celiac disease, Crohn's disease, and lupus. Canker sores can be cure with home remedies, and prescription and OTC topical and oral medication.
Cold Sores (Fever Blisters) PictureCold sores, sometimes called fever blisters, are groups of small blisters on the lip and around the mouth. See a picture of Cold Sores (Fever Blisters) and learn more about the health topic.
The Early Stages of Mouth CancerMouth cancer is also referred to as oral cancer. It is one of the cancers occurring in the head and neck region. It can arise from any part of the oral cavity, such as the lips, tongue, gums (gingiva), palate, the floor of the mouth, and the inner lining of the cheeks (buccal mucosa). Mouth cancers are locally invasive; it spreads to other parts of the head and neck, and eventually, the rest of the body.
ToothacheA toothache is pain on or around a tooth. It may have a variety of causes, including a cavity, abscess, or even sinusitis. Toothache symptoms include pain, headache, earache, bad taste in the mouth, and gum swelling. Dental X-rays and other tests performed by a dentist are used to diagnose the cause of a toothache. Toothache treatment depends on the underlying cause. Taking proper care of the teeth and gums can help prevent toothache.
Mouth Problems: TMJ, Canker Sores, Painful Gums and MoreSores, painful gums, bad breath -- what's going on in your mouth? Find out with our slideshow of the most common mouth problems. Learn about canker sores, cold sores, oral thrush, TMJ, and oral cancer. See what treatments for bad breath and other dental problems are available from your dentist.
What Are the Causes of Mouth Ulcers?Mouth ulcers are also called canker sores, aphthous ulcers, and are a form of mouth sores. They are small, round ulcers that may be red, yellow, or gray. They occur in lining of the oral cavity (mucous membrane), usually on the inner surface of the lips and cheeks. The causes of mouth ulcers can be traumatic, environmental, systemic disease, or medication. Quite often, mouth ulcers are triggered by an underlying medical condition.
What Causes Blisters on Lips?What are blisters on lips and what causes blisters on lips? Learn about these mouth sores, what causes blisters on lips, and how to treat blisters on lips. What to know about getting rid of blisters on the tongue. Learn about the causes of blisters on the tongue and possible treatment methods.
What Causes Blisters on Your Feet?What are foot blisters and what causes them? Learn about the types of foot blisters, what causes them, and how to treat them.
Why Do I Keep Getting Canker Sores in My Mouth?Canker sores are small open ulcers that usually appear on the inside of your mouth. Causes include stress, hormonal changes, nutritional deficiencies, foods and more. Although cold sores and canker sores have similarities, they are entirely different conditions. Canker sores are not contagious, but cold sores are. Canker sores show up inside the mouth, while cold sores are often seen on the lips.