Why Do My Gums Bleed, and When Is It Gum Disease?

Gums that bleed when you brush or floss are most often inflamed by plaque along the gumline, which is gingivitis, the earliest and reversible stage of gum disease. Bleeding can also come from brushing too hard, hormone changes, some medications and, less often, other health conditions. If it has not settled within about two weeks of careful cleaning, it is time for an exam.

Why do my gums bleed when I brush?

Plaque is a sticky film of bacteria that forms on teeth every day. When it sits along the gumline, the gum reacts with inflammation: it turns red, swells and bleeds easily. Cleveland Clinic calls bleeding gums the number one symptom of gingivitis and other forms of gum disease.

Other common reasons gums bleed include:

• A hard toothbrush or heavy pressure, or starting to floss after a long break
• Hormone changes during puberty, pregnancy or menopause
• Medications that thin the blood, or that dry the mouth and reduce saliva
• Vitamin C or vitamin K deficiency
• Less commonly, diabetes, blood clotting disorders or other medical conditions

A one-off bleed after biting something sharp is rarely a concern. Gums that bleed regularly, without an obvious reason, are worth checking.

What does it mean when gums are red and swollen?

Healthy gums are firm and pale pink and fit snugly around the teeth. Red, puffy or tender gums are the visible sign of inflammation. The American Academy of Periodontology (AAP) notes there is usually little or no discomfort at the gingivitis stage, which is why it is easy to ignore.

The good news is that gingivitis is reversible. The ADA and NIDCR both say early gum disease can usually be cleared up with a professional cleaning followed by thorough daily brushing and flossing at home.

When does bleeding mean periodontitis?

Left alone, gingivitis can progress to periodontitis. Plaque spreads below the gumline, the gum pulls away from the tooth and forms pockets, and the bone that holds the teeth starts to break down. That bone loss does not grow back on its own. The ADA reports that chronic periodontitis affects 47.2% of U.S. adults over 30.

Signs that suggest more than gingivitis include:

• Bad breath or a bad taste that does not go away
• Gums that are receding, so teeth look longer
• Teeth that feel loose or have shifted, or a bite that feels different
• Pus between the teeth and gums

Gum disease can also be silent: the AAP notes symptoms may not appear until advanced stages. That is why a dentist measures it rather than relying on how your gums feel. NIDCR explains that a small probe is used to measure the pockets around each tooth. In a healthy mouth they are usually between 1 and 3 millimeters, and deeper pockets can be a sign of periodontal disease. X-rays show whether bone has been lost.

Is gingivitis contagious?

Not in the way a cold is. Cleveland Clinic explains that gingivitis itself is not considered contagious, but the bacteria involved can pass between people through saliva. You are not likely to get gingivitis from a kiss or a shared fork, though people with poor oral hygiene or weakened immunity may be more susceptible. Your own daily cleaning matters far more than who you share a glass with.

What makes gum disease more likely?

NIDCR names smoking and tobacco use as the most significant risk factor. Tobacco also slows healing and makes treatment less successful. Other factors include older age, diabetes, genetics, stress, hormonal changes and some medications. Gum disease is more common and more severe in men than in women.

What is a deep cleaning (scaling and root planing)?

When pockets have formed, a regular cleaning cannot reach the deposits below the gumline. Scaling and root planing is a deeper cleaning: scaling removes hardened plaque (tartar) and bacteria from the tooth and root surfaces, and planing smooths the roots so bacteria have a harder time reattaching. The area is numbed first.

Cleveland Clinic describes it as typically taking one to two hours, sometimes split into two visits with half the mouth treated at each. Gums may feel sore for a couple of days, and teeth can be more sensitive to hot and cold for a while, which usually fades within a month or two. Most people go back to their normal routine the same day.

Gum disease is managed over time rather than fixed once. After treatment, a dentist will usually suggest more frequent cleanings to keep the pockets from filling up again. You can read more about how this works on our gum therapy page.

What should you do if your gums bleed?

• Keep brushing, twice a day with a soft brush and fluoride toothpaste. Avoiding the bleeding area lets plaque build up further.
• Clean between your teeth once a day with floss, interdental brushes or a water flosser.
• If you smoke, this is one of the strongest reasons to stop.
• Book an exam if the bleeding has not improved in about two weeks, or sooner if you notice loose teeth, receding gums or swelling.