Some people experience submandibular swelling bilaterally or unilaterally after eating, especially after eating foods that stimulate saliva production (like acidic foods), and the symptoms of swelling will gradually decrease after a period of time. The common cause of this symptom is caused by submandibular duct stones, submandibular duct stones are a kind of salivary stone disease (when stones are formed in the salivary ducts or glands and cause a series of symptoms and pathological changes, it is called salivary stone disease, now it is an obstructive disease the disease is uncommon, the incidence of middle-aged men is high). Common causes ① anatomical factors, submandibular gland secretion of saliva, against gravity secretion to the oral cavity, and into the oral cavity there is a turn, easy to cause salivary retention; another, duct inflammation often causes lumen narrowing, tumor compression, or foreign body obstruction, etc. so that saliva discharge is blocked, stagnant in the duct and glandular alveoli, gradually concentrated, which inorganic salt content increased and deposited to form salivary stones. ②Foreign body: When there is a foreign body in the duct or gland, the inorganic salts are deposited in layers as the core and gradually increase to form stones. In addition to the symptoms of swelling and pain after eating, stones can be palpated on examination, and pus is often visible in the duct opening, and X-ray examination can show stones. Treatment, mostly surgical, if the stone is located in the front end of the duct, the stone can be simply taken, if the stone is located in the back end of the duct or in the gland, the gland needs to be removed, secondary infection cases should be treated with a combination of pathogenic treatment, antibiotics, support symptomatic. Prevention, the key is to drink more water, such as small stones, acidic food can be eaten to promote saliva secretion, stones can be discharged along the saliva; has been clearly ductal stones, should be contraindicated for salpingography.