Blood Blisters in Mouth: Causes, Possible Treatments, and When to See a Doctor

Blood Blisters in Mouth: Causes and Treatments

A blood blister in the mouth is often caused by cheek biting or some other trauma inside the mouth. Blood blisters that occur on the roof of your mouth, tongue, or cheek are red in color and filled with blood and other fluids. Other types of sores in the mouth can resemble blood blisters and can cause pain and discomfort when eating or talking. Also, consuming hot liquids can make the blister in your mouth even more painful.

Blood blisters usually go away on their own without any special treatment. Of course, you should avoid irritating any kind of red blister or sore in your mouth to help speed up recovery. However, sometimes oral blood blisters can be a sign of a more serious health condition. For example, low platelet count, nutritional deficiencies, and even oral cancer can cause recurring blood-filled blisters in your mouth.

In this article, you will learn about the various causes of blood blisters in your mouth. This information can help prevent blood blisters appearing and get rid of them quicker if they do appear. You will also find out when the appearance of bumps filled with blood in your mouth is serious enough to visit your doctor for a checkup.

What is a Blood Blister in the Mouth?

Blood blisters can appear anywhere in the oral cavity. Because blisters are often caused by an injury, they can appear on the side of the tongue or underneath it. Fluid-filled blisters also appear on the inside of the cheek, the roof of the mouth, or inside the lip.

According to the National Health Service in the United Kingdom, blisters form when fluid collects under damaged skin. Depending on the cause, blisters can be filled with blood, clear fluid, or pus.1

Some of the causes of injury that results in a blood blister in your mouth are friction, irritation from chemicals, or burning your mouth.

Blood blisters vs. Oral ulcers

One type of red sore in your mouth that looks like a blood blister is an oral ulcer. Many people mistake oral ulcers (or canker sores) for blood blisters because they can sometimes have a deep red color.

According to doctors on WebMD, mouth ulcers can appear on the inside of the cheek, the roof of your mouth, or on the tongue. They usually have a red edge with a lighter center. They cause the tissue inside your mouth to become very sensitive and can cause pain when consuming food or drink. Usually, spicy and acidic foods can trigger a mouth ulcer or aggravate it.2

One way to get rid of mouth ulcers that are causing you pain and discomfort it to rinse your mouth with a saltwater solution several times a day. Use it as an antimicrobial mouthwash to speed up healing and prevent infection of the ulcer. All you need to do is mix a teaspoon of salt with a warm glass of water and let it dissolve. Swish it in your mouth and spit it into the sink. Doctors from the NHS also recommend to avoid hard, spicy, salty, acidic or hot food and drink until the ulcer heals.17

Causes of Blood Blisters in Mouth

Knowing how to treat blood blisters effectively can help speed up the healing time. Here are some of the most common reasons why blood blisters can show up in your mouth.

Mouth injury

One of the most common reasons for a blood blister in the mouth is an injury or trauma. Injury to the delicate tissue in your mouth can happen because of poor-fitting dentures, accidentally biting your cheek, or being scraped by jagged teeth.

Doctor of Dental Surgery, Dr. David Murchison says that mouth blood blisters caused by injury are common on the inside of the cheek. The oral blood blisters usually quickly burst and leave you with a painful ulcer in your mouth.3

Another reason for blood blisters in your mouth is chronic cheek biting. This condition where people “chew” their cheek is also called morsicatio buccarum. According to the Annals of Dermatology, cheek biting or lip biting can be caused by stress. This can leave lesions on the area where the cheek biting occurred.4

Big blood blister in mouth after tooth extraction

If you have had a tooth removed, then you may notice that a blood blister forms in the wound. The blister forms as fluid and blood form a clot under the skin of the wound.

Dr. Alfred Wyatt on WebMD says that you should be careful not to burst the blood blister after a tooth extraction. Therefore, you should avoid rinsing or spitting forcefully for 24 hours after having a tooth pulled, otherwise you could have a bleeding blister in your mouth. When brushing your teeth, you should avoid brushing the affected area until the wound has healed completely.5

If you had a wisdom tooth removed, you can read my article on wisdom tooth pain relief: the top 10 home remedies for more information.

Food allergies

Having an occasional blood blister could be linked to a food allergy or having sensitive tissue in your mouth. These food allergies can cause irritation in your mouth resulting in redness and swelling or they can cause mouth blisters to form.

According to the American Academy of Oral Medicine, some of the most common foods that cause hypersensitivity in the mouth are nuts, shellfish, milk, eggs, and some fruits and vegetables. Allergic reactions to these allergens can cause red blisters that develop into bloody crusts or swelling and redness in the oral cavity.6

Dr. David Murchison also says that cinnamon flavoring or acidic foods can cause mouth sores.3

If you are bothered by allergic reactions, you can try some natural antihistamines to help reduce any allergy symptoms.

Celiac disease

Some people who have celiac disease develop mouth sores that look like blood blisters. Celiac disease affects how the body absorbs certain nutrients and minerals and causes an inflammatory reaction to gluten.

According to the Journal of the Canadian Dental Association, oral blisters and enamel defects can help identify celiac disease. For example, recurring blisters in the mouth are often associated with celiac disease. It is thought that a mineral or vitamin deficiency caused by malabsorption is to blame for the formation of mouth blisters and sores.7

Angina Bullosa Hemorrhagica

Large blood and fluid-filled blisters in the mouth could be caused by a condition called angina bullosa hemorrhagica (ABH). According to Dr. Mark Duffill on DermNetNZ, trauma, diabetes, or hereditary factors can cause these large blood blisters to appear in the mouth.8

The Indian Journal of Dermatology says that blood-filled blisters caused by ABH are usually on the roof of the mouth or soft palate. However, it’s not uncommon that blood blisters appear on the side of the tongue or gums. Blistering usually happens quickly and it may take up to 10 days for the blister to drain and heal completely.9

Bullous pemphigoid

A problem with your immune system can cause large reddish blisters in the mouth. This condition is called bullous pemphigoid and can cause blisters to appear suddenly without any clear factors leading up to the blistering.

According to doctors from the Mayo Clinic, bullous pemphigoid usually affects the skin. However, it also causes blisters or sores to appear in the mouth. The condition tends to affect people over 60 and the blistering can get worse with age.10

Low platelet count

Another immune disorder that can cause blood blisters to develop in the mouth is having a low platelet count.

The University of California San Francisco says that some autoimmune conditions destroy blood platelets and this causes blood blisters in the mouth and on other areas of the skin. You may also bleed more easily or suffer from easy bruising.11

Nutritional deficiencies

Suffering from a nutritional or vitamin deficiency can cause blisters filled with red fluid in the mouth.

According to Dr. David Murchison, people lacking enough vitamin B, iron and vitamin C often suffer from mouth sores. This can cause sore red patches in the mouth that eventually develop into painful mouth ulcers.3

To find out more about vitamin B deficiencies and how to fix them, please read my article on the warning symptoms of vitamin B12. Also read my article about the top signs of iron deficiency and how to increase iron levels in your blood.

Oral herpes

The herpes simplex virus-1 (HSV-1) can cause painful red blisters on your soft palate, the inside of your cheeks, on your lips or gums. Many people carry the HSV-1 virus without showing any symptoms. However, if your immune system is weakened, you may get fluid-filled bumps or blisters in your oral cavity.

Dr. Charles Patrick Davis on eMedicineHealth says that the blisters in your mouth can appear in clusters and fill with fluid. When the blisters break, you are left with a light-colored ulcer on a red base. Along with the painful blisters, you may have a fever, fatigue, and muscle aches.12

There are many excellent ways to get rid of fever blisters (cold sores) naturally. For example, a simple paste made with baking soda and water applied to the blister can help to speed up the healing process.


Smoking has many detrimental health effects on the body including increasing the risk of mouth cancer, lung cancer, and gum disease. However, many people report that when they quit smoking they can suffer mouth lesions for a period of time.

A report in the journal Nicotine & Tobacco Research found that mouth ulcers were one of the withdrawal symptoms of giving up smoking. However, these oral lesions tend to only last for a couple of weeks before disappearing completely.13


Diabetes can cause complications that affect the mouth, including being a reason why fluid-filled blisters appear. Diabetes can also make you prone to infections which can affect the skin, gums, and nerves.

The American Diabetes Association reports that oral infections can cause problems in the mouths of diabetes sufferers. For example, red patches on the roof of your mouth, cheeks, or gums can appear because you are more prone to infections in the mouth. Or, you could have swelling that causes bumps anywhere in your mouth.14

It’s important to eat healthily to prevent the onset of diabetes. If you suffer from diabetes, your doctor may recommend controlling your diabetes naturally by diet.

Certain medications

Certain medications cause side effects that result in oral blood blisters or mouth sores and ulcers.

Doctors from the Mayo Clinic say that in some people, penicillin and some arthritis and anti-inflammatory drugs can cause blood blisters in their mouth.10

Teething blisters (in babies)

You may notice small blood blister on your baby’s gums when they start teething. This happens as the new teeth cause a little bleeding under the gums and results in a red-colored blister.

The website Parenting and Child Health reports that the blood blister should go away when the teeth come through. You don’t need to treat the blister as pricking it could cause a deeper infection. However, you should see your dentist if no teeth come through and there is still a blister.15

Oral cancer

A persistent blood blister in your mouth that doesn’t go away could be a sign of mouth cancer. According to the Victoria State Government, a blood blister that doesn’t go away or an ulcer that bleeds should be investigated to rule out the possibility of cancer. Other symptoms of oral cancer are difficulty in moving the jaw or tongue, speech changes, or an altered taste in the mouth.16

Should You Pop a Blood Blister in Mouth?

It is not recommended to pop or burst a blood blister in your mouth. The NHS says that most blisters don’t need any medical treatment and should heal naturally.1

When to See a Doctor

If the blood blister in your mouth doesn’t heal or is very painful, you should visit your doctor for a full examination. Dr. Mary Harding on says that any mouth lesion that hasn’t healed within 3 weeks should be seen by a doctor or dentist.

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Article Sources

  1. NHS. Blisters.
  2. WebMD. Mouth ulcers.
  3. MSDManuals. Mouth sores and inflammation.
  4. Ann Dermatol. 2012 Nov; 24(4): 455–458.
  5. WebMD. Having a tooth pulled.
  6. MAAOM. Oral hypersensitivity reactions.
  7. J Can Dent Assoc. 2011;77:b39
  8. DermNetNZ. Angina bullosa haemorrhagica.
  9. Indian J Dermatol. 2013 Sep-Oct; 58(5): 407.
  10. MayoClinic. Bullous pemphigoid.
  11. UCFSHealth. Immune thrombocytopenia.
  12. eMedicineHealth. Oral herpes.
  13. Nicotine Tob Res. 2004 Aug;6(4):655-9.
  14. Diabetes. More on the mouth.
  15. CYH. Teeth – development and teething.
  16. BetterHealth. Mouth cancer.
  17. NHS. Mouth ulcers.

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