Swollen gums eating watermelon will become more and more painful may be caused by poor oral hygiene, periodontitis and gingivitis. 1. Poor oral hygiene: If you are not able to clean some residual substances around the teeth in a timely manner, it will make the bacteria in the gum area grow and become infected, and the phenomenon of swollen and painful gums may occur, coupled with the stimulation of sugar in the watermelon, it will lead to more and more pain when you eat watermelon. 2. Periodontitis: Periodontitis patients due to periodontal infection, resulting in the phenomenon of swollen and painful gums. The sweetness of watermelon is relatively high, which may lead to increased inflammation of the teeth, thus causing increased pain. 3. Gingivitis: due to food blockage, poor restorations and other factors can promote the accumulation of plaque, which triggers gingivitis, and the emergence of gingival swelling and pain, bleeding gums and other symptoms. The high sweetness of watermelon leads to increasing pain. When patients with swollen and painful gums are getting more and more painful after eating, it is recommended to go to the hospital stomatology department for examination and treatment in time to avoid delaying the condition.