Sudden swelling on the cheeks of children may be caused by mosquito bites, trauma, mumps and other factors. 1. mosquito bite: such as bees, mosquitoes and other insects, the tail of the needle-like material contains anthranilic acid, hyaluronic acid and other substances, the child’s cheeks by bees, mosquitoes and other insects bites are prone to red and swollen symptoms. 2. trauma: due to the stimulation of some external factors, the child’s cheeks are damaged, and the local subcutaneous tissues of the skin of the cheeks bleed, which leads to the phenomenon of swelling of the cheeks. 3. mumps: mumps can be caused by bacterial infection or decreased immunity, manifested by fever, loss of appetite, swelling of the parotid glands and other symptoms, so the child’s cheeks suddenly swollen may be suffering from mumps disease. There may be other reasons for the sudden swelling of the child’s cheeks, so it is recommended that the child be taken to the hospital to complete the relevant examinations, to clarify the cause of the disease, and to be treated as soon as possible, so as not to miss the opportunity to treat the disease.