Causes of Blood Blisters in the Mouth

The formation of a blood blister in the mouth would seem to be a somewhat rare occurrence, since most of these types of blisters usually form as a result of pinching or a related type of trauma. When you get a normal blister, it is generally the result of rubbing an area of the skin to the point that fluids flow to the affected area as a means of protecting the layers of skin lying beneath the surface.

While these “normal” blisters will sometimes contain a certain amount of blood, in most cases they do not. Instead, they are usually filled with lymphatic fluids. As this fluid accumulates, swelling occurs and a blister forms.

What makes a blood blister different is, of course, obvious. The fluid involved is blood plasma. This problem occurs because a blood vessel has ruptured, which is usually not the case with other blisters. When a blood vessel near the surface of the skin breaks, blood will seep out beneath the skin. Since it is under pressure, it is forced out with enough energy to create a bulge in the skin. While the skin itself is not transparent, the outer layer is somewhat translucent, so the pool of blood lying beneath the skin is visible.

There are numerous reasons why one or more of these blisters may form in the oral cavity. Listed are the more common causes expressed in general terms:

How You Eat

One of the more common ways a blood blister can form has already been mentioned. The blister is formed by pinching. In this case, the pinching occurs between the surfaces of your upper and lower teeth. If a blister forms, it will usually do so on the inside of your cheek, and most often occurs while eating. If you bite down on the soft tissue in your mouth, it is generally the tongue that bears the brunt of the punishment, but if you happen to bite the inside of your cheek and cause a blood vessel to rupture, you will likely end up with a blister. Cheek biting resulting in a blister usually happens when you are eating but not paying attention to how you are eating. If your thoughts are far away while you are chewing your food or if you’re talking to someone else (which you shouldn’t be doing with food in your mouth anyway), you may accidentally bite your cheek. The same thing can happen if you are eating too fast, in which case you may be negligent about how you are chewing your food. These little injuries tend to be self-inflicted.

What You Eat

Chewing your food is not the only way to create a blood blister while eating. Food that is too hot can cause a blood vessel in the mouth to pop, as can hard candies or food that has a sharp edge, like a piece of toast or the crust of a bun. Most of the time when you bite something hard or sharp, nothing happens. If there is pain, it may be a sharp pain that goes away almost as quickly as it comes. A liquid that can cause blisters to form is alcohol. Drinking in moderation rarely causes blisters to form, but if alcohol is being abused it can be a different story.

Allergies and Medications

Another way the food you eat can be a culprit is if you have an allergy to a particular type of food or a chemical compound that has been put into the food. Just as an allergy can cause a rash and bumps on your skin, a food allergy can cause inflammation on the inside of your mouth, sometimes leading to the formation of one or more blisters. The same is true of certain medications. It is not uncommon for a medication to cause side effects, and these side effects can sometimes occur in the form of an allergic reaction to an oral medication.

Ulcers and Diseases

The most common form of ulcer found in the mouth is the canker sore. These sores often appear to be white rather than red; the reason being is they often contain pus. Canker sores can, in some instances, contain blood, in which case they could be considered a type of blister. Oral ulcers are usually the result of an overgrowth of certain types of microorganisms in the mouth. These microorganisms can cause lesions and blisters to form in the mouth. The presence of the microorganisms is often due to an illness or disease, but sometimes medications can encourage their growth as well. A disease that probably causes more blisters to form in the mouth than any other is oral herpes. Oral herpes can cause blisters to form virtually anywhere in the oral cavity. These blisters can often be quite painful.

Secondary Causes

There are some things that can cause the formation of one of these blisters, but do so only indirectly. If you have a low platelet count, your blood will not clot as easily. When this is the case, a ruptured blood vessel will flow more freely and for a longer period of time, giving a blister more of a chance to develop. Those who have a chronic low platelet condition are often much more susceptible to these blisters. The same is true for a nutritional deficiency. If you don’t eat your spinach, or more precisely if you aren’t getting enough vitamin C or vitamin B12, you run a higher risk of experiencing blisters at one time or another.

How much irritation or actual pain is caused depends upon a number of things. A blister will generally not present too much of a problem for you if pressure is not being applied to it. It would make sense, therefore, that a blister on the inside of a cheek would tend to be less painful than one on the lips or tongue. One that forms on your gums may not bother you until it’s time to brush your teeth. It could then become very painful, though.

Eat carefully and you may never experience one these little nuisances on your lips, tongue, or elsewhere in your mouth. It may be next to impossible, though, to go through life without ever having one of these blisters form, but your health and lifestyle definitely make the risk of it happening either increase or decrease.