Skip to content


    Attention All WebMD Community Members:

    These message boards are closed to posting. Please head on over to our new WebMD Message Boards to check out and participate in the great conversations taking place:

    Your new WebMD Message Boards are now open!

    Making the move is as easy as 1-2-3.

    1. Head over to this page:

    2. Choose the tag from the drop-down menu that clicks most with you (and add it to any posts you create so others can easily find and sort through posts)

    3. Start posting

    Have questions? Email us anytime at [email protected]

    Includes Expert Content
    small blood blister on back gums
    Kaydee040809 posted:
    My sister has a tiny blood blister in the back of her mouth behind her last molar tooth.She noticed it today when brushing so not 100% certain how long its been there but assuming just 24 hours.It is about the size of the tip of a ball piont pen maybe slightly bigger.It doesnt hurt her,but shes concerned of the cause and wondering wether or not its something that might need professional care.Any advice would be appriciated.
    Zev Kaufman, DDS responded:
    Dear Kaydee040809:

    The general rule of thumb when it comes to the mouth and mouth lesions is "two weeks", especially when there are no other symptoms such as pain.

    If the sore, blister, etc. is there for over two weeks it is time to go and see your dentist.

    The chances are that the sore is just a blood blister caused by trauma such as biting into something hard.

    Since you do not know when it started and you have noticed it for about a week, wait until the end of the upcoming week. If it is gone, it was probably caused by trauma. If it is still there, please go see your dentist for a correct diagnosis.

    Best wishes,
    Dr. Zev Kaufman

    Helpful Tips

    sinus trouble in my teeth
    need info on sinus that have gotten into my teeth i went to the dentist this week and my dentist told me about this and i have never heard ... More
    Was this Helpful?
    9 of 19 found this helpful

    Related Drug Reviews

    • Drug Name User Reviews

    Report Problems With Your Medications to the FDA

    FDAYou are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

    For more information, visit Dr. Kaufman's website