Healthy gums should be a light pink colour. If they’re a deeper pink or red, if they bleed when brushed, or if they’re tender to the touch, this may be a sign of gingivitis. This is an accumulation of bacteria, otherwise known as plaque, that is brought on by inadequate oral hygiene. Left untreated, this in turn hardens into tartar, which is hard to remove. Gingivitis is the first stage of gum disease, and is treatable with improved oral hygiene. If left untreated, it can worsen into periodontal disease.