Gums that bleed when you brush.

A little pink on the toothbrush is one of the most common things people notice about their mouths, and one of the most commonly ignored. Bleeding gums are not normal, but they are usually simple: the gum is reacting to plaque that has been left at the gum line, and it is telling you where. At this stage, gingivitis, it is fully reversible, and most of the reversing happens at home.

Why gums bleed

Plaque forms on teeth within hours of cleaning. Left for a day or two at the gum line, it provokes an immune response: the gum becomes slightly swollen, redder at the edge, and bleeds when brushed. The instinct is to brush that spot less. The answer is to brush it more thoroughly, and more gently. During pregnancy gums bleed more easily for a while; so do gums in someone whose diabetes is not well controlled, or who has recently started a blood-thinning medicine: worth mentioning, not worth stopping.

The two-week routine

Brush twice a day for two full minutes with a soft brush, angled toward the gum line, using small movements and light pressure: the bristles should barely bend. Clean between every tooth once a day, with floss or interdental brushes; the gaps between back teeth are where most bleeding starts. Expect the bleeding to continue, or even increase slightly, for the first few days as inflamed gums are cleaned properly. By the end of two weeks it has usually stopped. A plain fluoride toothpaste is all that is needed.

What does not help

Mouthwash on its own: it freshens, but it does not remove plaque, and it cannot reach below the gum line. Stopping brushing the bleeding spot. Hard brushing, which wears the gum away rather than cleaning it. Salt or clove oil rubbed on the gum, which soothe for a few minutes and change nothing.

When to come in

If the bleeding has not settled after two to three weeks of the routine; if gums are bleeding on their own, without brushing; if teeth look longer than they did, feel loose, or have started to drift; if there is a taste or breath concern that does not shift; or if you have never had your gums measured. An examination measures the gum around each tooth and looks at the bone on an X-ray, which is the only way to tell surface inflammation from gum disease that has gone deeper. A professional clean removes the hardened plaque a brush cannot, and a short demonstration shows where the brush was missing: the most useful ten minutes of the visit.

The explainer on how gum disease damages the bone under your teeth covers what happens if it is left; the gum treatment page explains what treatment involves.