Problems in maintaining dental care is the most common cause of bleeding gums. The main cause of bleeding gums is the buildup of plaque at the gum line. This will lead to a condition called gingivitis, or inflamed gums.
Plaque that is not removed will harden into tartar/calculus. This will lead to increased bleeding and a more advanced form of gum and jaw bone disease known as periodontitis.
Other causes of bleeding gums include: