Swelling and pain on the inside of the upper gums may be caused by diseases such as apical periodontitis and oral ulcers, corresponding to the need for root canal treatment or medication. 1. Periodontitis. Swelling and pain on the inside of the upper gums may be caused by apical periodontitis, inflammation in the apical area through the periosteum to reach the submucosa, causing redness, swelling and pain in the gum area, root canal treatment is needed to remove the infected pulp to eliminate the inflammation. 2. Oral ulcers. When hard object stimulation or the body’s own factors can cause oral ulcers on the palate, need to remove external stimuli, such as bad restorations, sharp tips, the use of anti-inflammatory drugs to promote healing, such as cediriodine tablets, tretinoin ointment and so on. Swelling and pain on the inside of the upper gums, it is recommended to go to the hospital in time to deal with, to avoid the spread of inflammation, affecting work and life. The medication should be prescribed by the doctor.