The most common cause of bleeding gums is the build-up of plaque and tartar (calcified plaque) that have been accumulating over a period of time.
Smoking, some medical conditions and pregnancy usually make gums more inflamed than usual. Sometimes gum can get irritated or traumatised from food impaction, aggressive brushing and flossing.
Regular removal of plaque and tartar by your dentist is needed every 6-12 months followed by oral hygiene instruction.
X ray might need to be taken to check for underlying problems.
Inflamed gums can look unattractive and result in bad smell and taste.
It can also lead to periodontitis which is the serious type of gum disease that involves gum and bone loss.