There are many reasons for swollen gums without pain, such as gingivitis, pulpitis, wisdom teeth pericoronitis, external stimulation and so on. 1. Gingivitis: Infection of the gum tissue by pathogenic bacteria can cause swelling of the gums, with atypical symptoms, which can also lead to the phenomenon of swollen gums without pain. 2. Pulpitis: Mostly due to tooth decay or other causes of dentin damage, resulting in pulp infection, may also lead to gum swelling without pain. 3. Wisdom tooth pericoronitis: Wisdom teeth squeeze the neighboring teeth, or secondary infection, which can also lead to swollen and painless gums. 4. External stimulation: for example, by the outside world of the extrusion, injury, or take too hot, too spicy, too hard and other stimulating food, may also lead to gum swelling and pain. Gums are swollen, there may be other reasons, you need to go to the hospital in time to check, clear the cause of the disease after treatment.