It is best not to smoke when the gums are swollen and painful, as this can aggravate the inflammation and increase the pain of the patient. The main causes of swollen and painful gums are gingivitis and periapical abscess. Gingivitis is caused by a large amount of plaque, calculus, soft tartar and other undesirable irritants attached to the surface of the teeth, which presses on the periodontal tissues and leads to gingivitis. Smoking can irritate periodontal support tissues such as the gums, leading to localized hypoxia, which promotes tooth pigmentation, plaque and calculus deposition, and irritation of the gums. Periapical abscess is an inflammatory disease that occurs in the tissues surrounding the root of the tooth, as inflammation builds up, an abscess is formed and the pus spreads in the direction of the root of the tooth, causing swelling and pain in the gums. And smoking has a sucking action, the pressure in the mouth will increase, which will easily lead to the spread of abscess, further aggravate the condition and increase the patient’s pain. Patients with swollen and painful gums should follow the doctor’s instructions to actively cooperate with the doctor’s treatment, do not smoke, so as not to cause adverse reactions.