Toothsmith Dental Surgery Singapore

Why do my gums bleed when I brush?

Reviewed by Dr Samuel Ong Jien Woon, BDS (Singapore), Clinic DirectorLast reviewed 4 November 2026General information, not a diagnosis
Short answer: The most common cause is gingivitis: plaque left along the gum line inflames the gums, which then bleed when brushed or flossed. It is reversible. Keep brushing gently twice a day, clean between your teeth daily, and have a scaling to remove hardened tartar; bleeding usually improves within one to two weeks. See a dentist if bleeding persists, your gums are receding, teeth feel loose or there is pus. See a doctor if your gums bleed on their own along with easy bruising, fatigue or nosebleeds.

Gingivitis and gum disease

Plaque is a soft film of bacteria that forms on teeth every day. Where it is not removed, especially along the gum line and between teeth, the gums become red, puffy and bleed easily. This is gingivitis. It usually does not hurt, which is why it is easy to ignore.

If plaque hardens into tartar and inflammation continues, it can progress to periodontitis: the gum and bone that hold the teeth are slowly lost, pockets form around the teeth, and teeth can eventually loosen. Periodontitis is a common cause of tooth loss in adults, and it is often painless until late.

GingivitisPeriodontitis (see a dentist)
Bleeding on brushing or flossingBleeding plus receding gums, teeth looking longer
Red, puffy gum edgesPersistent bad breath or bad taste
Reversible with good cleaning and scalingLoose or shifting teeth, gaps appearing, pus

What to do

  • Do not stop brushing the areas that bleed. Bleeding is a sign that the area needs more gentle cleaning, not less.
  • Brush twice a day for two minutes with a soft brush and fluoride toothpaste, angling the bristles towards the gum line.
  • Clean between your teeth once a day with floss or interdental brushes. Expect some bleeding for the first week; it should then reduce.
  • Book a scaling. Tartar cannot be brushed off. See check-up and scaling costs.
  • If you smoke, be aware that smoking can hide bleeding while gum disease gets worse.

Other causes of bleeding gums

  • Pregnancy: hormonal changes make gums react more to plaque. See dental care in pregnancy.
  • Blood thinners such as warfarin, apixaban, rivaroxaban, clopidogrel or aspirin. Do not stop them; tell your dentist.
  • Diabetes, especially when not well controlled, raises the risk and severity of gum disease.
  • Starting to floss, or brushing too hard with a hard brush.
  • Vitamin C deficiency, which is uncommon with a normal diet.
  • Rarely, a blood disorder. If your gums bleed without brushing, or you also have easy bruising, nosebleeds, fatigue or frequent infections, see a doctor.

Treatment at the dentist

Your dentist checks the depth of the gum pockets, may take X-rays to look at the bone, and removes tartar by scaling. Deeper gum disease may need cleaning below the gum line over more than one visit, and a review a few weeks later. Scaling and polishing are CHAS-claimable for eligible cardholders. See gum care.

Frequently asked questions

Can gingivitis go away on its own?

Not without removing the plaque that causes it. With daily brushing, cleaning between the teeth and a scaling, gingivitis usually improves within one to two weeks.

What vitamin deficiency causes bleeding gums?

Severe vitamin C deficiency can cause bleeding gums, but it is uncommon. Plaque-related gingivitis is far more often the cause, so have your gums checked before taking supplements.

Is it normal for gums to bleed when flossing?

When you first start, some bleeding is common and should reduce within a week or two of daily flossing. Bleeding that continues means the gums are still inflamed.

Is bleeding gums a sign of cancer?

It is rarely the cause. If bleeding is spontaneous or comes with bruising, fatigue, fever or weight loss, see a doctor promptly.

Sources

  • European Federation of Periodontology, Oral health and pregnancy: key messages

Questions about your teeth?

Book a check-up. You will hear what we find, the options and the fee before anything is done.

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