If you notice blood in the sink after flossing, you are not alone; it is a common experience. However, bleeding gums signal that the tissue is not entirely healthy. Flossing removes the sticky, bacteria-laden film known as plaque from the tight spaces between teeth and beneath the gumline. Healthy gum tissue should be firm and pale pink, and it should not bleed during this routine cleaning process.
Inflammation Caused by Plaque Buildup
The most frequent reason for bleeding during flossing is plaque-induced inflammation in the gum tissue. Plaque is a biofilm of bacteria that accumulates along the gumline. These bacteria release toxins that irritate the soft tissue, triggering a localized immune response. This causes the gums to become red, slightly swollen, and tender, an early stage of inflammation known as gingivitis.
Inflamed tissue contains an increased volume of blood and has delicate blood vessels near the surface, making it highly susceptible to trauma. When floss passes through, the physical disturbance easily ruptures these capillaries, resulting in noticeable bleeding. This bleeding is a direct consequence of the underlying inflammatory process, not the flossing itself. Gingivitis is reversible; consistent plaque removal allows the inflammation to subside and the gums to return to a healthy state. If plaque is not removed, it can harden into a rough deposit called calculus, which further exacerbates irritation and cannot be cleaned effectively with home care alone.
Factors Beyond Gum Disease
While plaque accumulation is the primary cause, bleeding gums can also be triggered by issues unrelated to chronic disease. If you recently started flossing after a long hiatus, your gums may bleed temporarily as they adapt to the new routine. This temporary sensitivity should resolve within a week or two of consistent daily flossing.
Hormonal fluctuations, such as those during puberty, pregnancy, or menopause, can increase blood flow to the gum tissue, making it more sensitive to flossing. Certain medications, particularly blood thinners, can make gums bleed more easily due to their effect on clotting ability. Underlying systemic health conditions can also manifest in the mouth. These include diabetes, which impairs the body’s ability to fight infection, and deficiencies in nutrients like Vitamin C or K, which are necessary for tissue health and blood clotting.
Correcting Your Flossing Method
Bleeding may also be a sign that your mechanical technique is causing self-inflicted trauma. Aggressive flossing, or snapping the floss forcefully between the teeth, can cut or bruise the delicate gum tissue. Effective flossing requires control, starting with using an appropriate length of floss, generally about 18 inches, wrapped mostly around your middle fingers.
The most effective technique involves forming the floss into a “C” shape around one tooth once it passes the contact point. This curve allows the floss to gently hug the tooth’s surface and slide slightly into the space beneath the gumline, known as the sulcus. Use gentle up-and-down strokes along the side of the tooth, moving the floss from the gumline toward the biting surface. Unroll a fresh, clean section of floss for each tooth to prevent transferring bacteria from one area of the mouth to another.
When to Seek Professional Dental Care
If bleeding persists despite two weeks of correct and consistent flossing, schedule a professional dental evaluation. Persistent bleeding indicates that gingivitis has progressed or that plaque has calcified into hard tartar, which cannot be removed by flossing alone. If untreated, gingivitis can advance to periodontitis, which involves the destruction of the bone and supporting structures around the teeth.
Signs of advanced gum disease include chronic bad breath, visibly receding gums, a change in the fit of your bite, or loose teeth. A dental professional can accurately diagnose the cause of the bleeding and perform a thorough cleaning to remove the hardened deposits. This procedure, sometimes called scaling and root planing, cleans deep beneath the gumline and is necessary to stop the progression of the disease and restore gum health.