Hand, foot and mouth disease (HFMD) is an acute infectious disease caused by an enterovirus infection that occurs mostly in preschool children, with the highest incidence especially in children under 3 years of age. Most HFMD are generalized cases presenting with an acute onset of fever, scattered herpes on the oral mucosa, and maculopapular and herpetic rashes on the hands, feet and buttocks. The herpes is surrounded by an inflammatory redness, with little fluid in the blisters. It may be accompanied by cough, runny nose, loss of appetite, nausea, vomiting, headache, etc. Some cases present only with a rash or herpetic pharyngitis. Cure is good, no sequelae, and the rash usually subsides in 7-10 days. However, there are some severe cases of HFMD, and parents must identify them as early as possible to avoid delaying their children’s illness. In severe cases, encephalitis, encephalomyelitis, meningitis, pulmonary edema, circulatory collapse and other complications may occur. Neurological symptoms include poor mental health, drowsiness, headache, vomiting, easy startle, limb tremors, weakness or paralysis; physical examination may show meningeal irritation and weakened or absent tendon reflexes; critical cases may show frequent convulsions, coma, cerebral edema and brain herniation; respiratory symptoms include shallow and difficult breathing, altered respiratory rhythm, cyanosis of the lips, white, pink or bloody foam (sputum); sputum may be heard in the lungs In the circulatory system, the child’s face is pale, the heart rate increases or slows, the pulse is shallow, weak or even disappears, the extremities are cold, the fingers (toes) are blue, and the blood pressure is elevated or decreased. “If the child is younger than three years old, persistent high fever that does not subside, poor peripheral circulation, markedly increased respiration and heart rate, poor spirits, vomiting, convulsions, shaking or weakness of the limbs, markedly increased peripheral blood leukocyte count, hyperglycemia, hypertension or hypotension. Children with these characteristics are likely to develop into critical cases within a short period of time, and parents should closely observe changes in their children’s condition.” Early recognition of severe manifestations of HFMD is important for timely treatment. “Hand, foot and mouth disease is a preventable and treatable disease, and when children are found to have the disease, they must be treated in a timely manner to avoid deterioration and other complications. Mild cases can be treated at home, but severe cases must be identified early and seen in hospital early to avoid delays.” To effectively prevent this disease, children should exercise more, strengthen their resistance, eat a reasonable diet, not eat cold and barbecued foods, drink more water and eat more vitamin-rich fruits and vegetables. If a person with HFMD is found, he or she should be isolated and treated as soon as possible. Once infected with the disease, they should stay at home and stop sending them to child care centers.