What is a common symptom of gingivitis?

Bleeding gums is a common symptom of gingivitis, which is an inflammation of the gums typically caused by plaque buildup on the teeth. When the gums are inflamed, the tissues become sensitive and can bleed easily, especially during brushing or flossing. This symptom is an early indicator of gum disease and should prompt a dental evaluation and improved oral hygiene practices.

The other options do not represent typical symptoms of gingivitis. Severe pain is more characteristic of advanced periodontitis or other dental issues. Tooth mobility usually occurs in more severe stages of gum disease, indicating significant loss of supporting structures. Decay formation relates to dental caries, not gingivitis, as gingivitis itself does not directly cause tooth decay but rather impacts the health of the gums.