While it’s true that sometimes the reason is that you’ve brushed too hard, especially if it seems to be a one-off, most of the time bleeding gums are a sign of something more serious.
Gums should not bleed if you brush and floss properly on a regular basis. If you arent a routine flosser, bacteria buildup below the gums may cause your gums to bleed each time you brush. This can also spread along the gumlines and bleed when you brush your gums. If treatment is delayed, the bleeding usually worsens.