When gums bleed in the sink, the usual assumption is “I brushed too hard.” Sometimes that is true. But according to MedlinePlus, the main cause of bleeding gums is plaque buildup at the gum line, and the list of other possible causes runs from hormones and medications to diabetes and blood disorders. Bleeding gums are common, often easy to fix, and occasionally a sign of something that needs medical attention. Here are six causes worth knowing about, and how to tell when it is time to book a dental visit.
1. Is it early gum disease?
This is the most likely explanation. Plaque, a sticky film of bacteria, collects along the gum line when teeth are not cleaned thoroughly. The gums react with inflammation: they turn red, swell and bleed easily. That stage is called gingivitis. According to NIDCR, gum disease starts with swollen, red and bleeding gums, and if it is left alone it can progress to periodontitis, which damages the bone that holds teeth in place.
The good news is that early, plaque-driven gum disease can often be reversed with daily brushing and flossing, according to NIDCR. Once plaque hardens into tartar, though, only a dental professional can remove it.
Smoking deserves a special mention. NIDCR calls tobacco use the most significant risk factor for gum disease, and it can slow healing. MedlinePlus also notes that tobacco makes bleeding gums worse. For a fuller overview, see our topic page on bleeding gums when brushing.
2. Did you just change your flossing routine, or does a dental appliance not fit?
Gums that are not used to flossing often bleed for the first several days after you start, because they are already mildly inflamed. That is usually a reason to keep going gently, not to stop. Improper flossing, such as snapping floss down hard into the gums, can also cause bleeding, and MedlinePlus lists ill-fitting dentures and other dental appliances as a cause too.
If bleeding from a new routine does not settle within about two weeks, that is a signal that something else is going on. Cleveland Clinic advises seeing a dentist if bleeding gums do not improve within two weeks. If dentures or a retainer cause sore spots, a dentist can adjust them.
3. Could hormones be playing a role?
Hormonal shifts during puberty, pregnancy and menopause can make gums more reactive to plaque, according to Cleveland Clinic. Pregnancy is the classic example. The CDC estimates that 60% to 75% of pregnant women have gingivitis, which may be aggravated by changing hormones.
The CDC also states that dental care is safe and important during pregnancy, so bleeding gums are a reason to keep or schedule a cleaning, not to postpone it until after delivery. Let your dentist know you are pregnant.
4. Are you taking a blood thinner or another medication that affects bleeding?
Anticoagulants and other blood-thinning medications are listed by both Cleveland Clinic and MedlinePlus as causes of bleeding gums. Aspirin can contribute too; MedlinePlus advises avoiding aspirin unless a health care provider has recommended it.
Some supplements may add to the effect. For example, NCCIH notes that ginkgo may increase the risk of bleeding in people taking anticoagulants such as warfarin. If you take a blood thinner, tell your dentist, and review every supplement with your prescriber.
Important: never stop or change a prescribed blood thinner because your gums bleed. MedlinePlus is clear that you should ask your provider about alternatives rather than changing medicines on your own. Stopping these drugs abruptly can be dangerous.
5. Could blood sugar be involved?
Diabetes and gum disease feed each other. According to NIDDK, high blood glucose can build up in saliva and feed plaque-forming bacteria, diabetes and some of its medicines can reduce saliva, and high blood glucose increases the risk that gum disease progresses from mild to severe. Gum disease, in turn, can make blood glucose harder to control.
Cleveland Clinic notes that when someone has bleeding gums without gum disease, providers may test for diabetes. If you have been told your numbers are creeping up, our page on borderline blood sugar on a checkup and the blood sugar support hub explain next steps. If you already have diabetes, NIDDK recommends telling your dentist and seeing them right away if you notice mouth problems.
6. Could it be a nutrient deficiency or a blood disorder?
These causes are less common in the US, but they matter because they need medical, not just dental, care:
- Vitamin C deficiency (scurvy) and vitamin K deficiency are both listed by MedlinePlus. Severe vitamin C deficiency is rare today but can occur with very restricted diets.
- Clotting and platelet disorders, such as hemophilia, von Willebrand disease and thrombocytopenia, appear on Cleveland Clinic’s list.
- Leukemia can cause bleeding gums, according to both sources.
Clues that point away from a simple plaque problem include easy bruising, nosebleeds, bleeding that is hard to stop, fatigue, or bleeding gums despite healthy-looking gums and good hygiene. Do not self-treat with supplements in this situation; MedlinePlus advises taking vitamin supplements if you have been diagnosed with a deficiency, which means getting tested first.
What can you do at home in the meantime?
For most people, a better daily routine makes a visible difference within a couple of weeks. Drawing on MedlinePlus, Cleveland Clinic and NIDCR:
- Brush gently twice a day with a soft-bristled toothbrush and fluoride toothpaste.
- Clean between your teeth every day with floss, an interdental brush or a water flosser. Expect some bleeding at first.
- Stop smoking or using other tobacco products.
- Rinse with warm salt water, or use an antibacterial mouthwash if your dentist recommends one.
- To stop active bleeding, press a gauze pad soaked in ice water against the gum.
- Cut back on frequent snacking and sugary foods, which feed plaque bacteria.
- Keep regular cleanings, since only a professional can remove tartar.
Supplements are not a fix for bleeding gums, and ingredients marketed for gum health have limited evidence. If you are curious about what has been studied, our best-researched ingredients for oral health guide and the oral health hub give an even-handed overview. Bleeding gums often travel with persistent bad breath and can be worse with a dry mouth, so those pages may be useful too.
When to see a dentist or doctor
Do not wait this one out for months. Gum disease is far easier to treat early, and a dentist can tell within one visit whether plaque and tartar explain the bleeding. Make a dental appointment if:
- Your gums still bleed after about two weeks of gentle, consistent brushing and flossing (Cleveland Clinic).
- You notice swollen or receding gums, loose or sensitive teeth, pain when chewing, or bad breath that does not go away (NIDCR).
- You are pregnant, have diabetes, or take a blood thinner. Tell your dentist about these conditions and any medicines or supplements you take.
See a doctor promptly, not just a dentist, if bleeding is severe or long-lasting, continues after dental treatment, or comes with other unexplained symptoms such as easy bruising, frequent nosebleeds, fever or unusual fatigue, as MedlinePlus advises. Those signs can point to a clotting problem, a medication effect or another condition that needs a medical workup.
