Tobias K. Boehm (October 8, 2025)
Bleeding gums during dental exam (Dr. Boehm)
One of the rituals of getting a check-up at a dentist is having your gums checked for signs of gum disease. This involves a dentist, hygienist, or another staff member probing the gums with a metal probe and calling out various numbers. These numbers are entered into a chart that looks like this:
Example of a paper-based periodontal chart (Dr. Boehm)
The chart may be paper-based or an electronic version of it, but it always will have the same setup of numbers, symbols and teeth. In this series, we break down what these numbers and symbols mean.
In this article, we describe the term “bleeding on probing” or gum bleeding, which in this case is noted with dots above a number as shown here:
Depending on the practice and charting system, this might also be labeled as “B” like bleeding, or another symbol such as stars, asterisks, circles.
What does gum bleeding or “Bleeding on Probing” mean?
In most cases, gum bleeding signals inflammation in the gums, and usually that is from active gum disease. It is possible that bleeding from the gums can happen after frequent or heavy-handed probing. However, this type of bleeding looks typically different from that caused by gum disease. From the patient perspective, heavy-handed probing feels at least uncomfortable or is outright painful. From the provider perspective, bleeding will be slow to occur, usually a short time after probing, similar to bleeding from a skin scratch. Most importantly, bleeding from heavy-handed probing will appear from healthy pink gums.
While gum disease may make probing also uncomfortable, bleeding will happen even with light touch or it might be spontaneous. Bleeding will immediately follow probing, and blood will readily appear. With severe gum inflammation, blood may begin dripping from the probed site and there will be a taste of blood in the mouth. At that point, providers will usually use gauze and pressure to stop bleeding. This type of severe gum bleeding typically means severe inflammation of the gums, which is a sign of active gum disease.
What conditions cause gum bleeding?
- Most of the time, gum bleeding is caused by gum diseases such as gingivitis or periodontitis
- Short-lived gum bleeding can be caused by injuries to the gums, such as accidental cuts from sharp foods or flossing, or during dental procedures
- Rarely, gum bleeding can be caused by medical conditions such as
- Leukemia
- Bleeding disorders
- Anticoagulant medication overdose
- Autoimmune disorders targeting skin or soft tissue
When should I be concerned about gum bleeding?
Bleeding from the gums is never normal, and you should always consult a dentist if you notice bleeding from the gums. In most cases, dentists should be able to tell if the bleeding is from gum disease, gum injury or some other cause that needs medical attention.
Consult with a physician if in addition to gum bleeding you experience a high fever, sudden unexplained weight loss, skin blistering, large skin bruises or bleeding that does not stop on its own as these could be sign of serious medical conditions.
Why does gum bleeding happen?
When gum disease develops, several events happen at the tissue level that make gum tissue more likely to bleed during dental exams. Gum diseases typically are started by microbial changes on the tooth surface next to the gum tissue. These changes active the immune system, causing local inflammation in the gum tissue. The inflammation results in superficial blood vessels increasing in number (1). In addition, immune cells weaken the soft tissue by removing collagen fibers and causing microscopic ulcers on the gum tissue facing the infected tooth surfaces (2)
Consequently, probes inserted into this fragile tissue readily rupture small blood vessels and cause the gums to bleed during a dental exam.
How does gum bleeding influence treatment decisions?
Bleeding from the gums strongly suggests active gum disease. Deep gum pockets are more likely to also show bleeding on probing, and when there is bleeding from many sites, there is a high chance of losing tooth support (3). In the current classification of gum diseases, bleeding from more than 10% of sites checked during a dental exam distinguishes gum disease from healthy gums (“periodontal health”) (4).
Therefore, presence of bleeding on probing from more than 10% of sites will likely have a dentist recommend some form of gum disease treatment to you. This could range from changing your oral hygiene routine to increased frequency of cleanings or additional treatments such as scaling and root planing.
About the author:
Tobias K. Boehm, DDS, PhD, MBA, PC, DABP, DICOI, FGDIA is the founder of The Dental Institute, executive director at The Defeating Epilepsy Foundation and a professor at Western University of Health Sciences where he teaches and practices a periodontal specialist.
References:
(1) Matheny JL, Abrams H, Johnson DT, Roth GI. Microcirculatory dynamics in experimental human gingivitis. J Clin Periodontol. 1993 Sep;20(8):578-83. doi: 10.1111/j.1600-051x.1993.tb00774.x. PMID: 8408719.
(2) Saliem SS, Bede SY, Cooper PR, Abdulkareem AA, Milward MR, Abdullah BH. Pathogenesis of periodontitis – A potential role for epithelial-mesenchymal transition. Jpn Dent Sci Rev. 2022 Nov;58:268-278. doi: 10.1016/j.jdsr.2022.09.001. Epub 2022 Sep 16. PMID: 36159185; PMCID: PMC9489739.
(3) Lang NP, Joss A, Orsanic T, Gusberti FA, Siegrist BE. Bleeding on probing. A predictor for the progression of periodontal disease? J Clin Periodontol. 1986 Jul;13(6):590-6. doi: 10.1111/j.1600-051x.1986.tb00852.x. PMID: 3489010.
(4) Sutthiboonyapan P, Wang HL, Charatkulangkun O. Flowcharts for Easy Periodontal Diagnosis Based on the 2018 New Periodontal Classification. Clin Adv Periodontics. 2020 Sep;10(3):155-160. doi: 10.1002/cap.10095. Epub 2020 Apr 8. PMID: 32073220.