After being infected with the virus for 3 to 5 days, the symptoms appear, including rash oral cavity, palm, feet, blisters and ulcers, etc., and sometimes these symptoms combine with fever. But most of the infected patients do not have clinical symptoms, or the clinical symptoms are very minor. In most cases, the symptoms naturally heal after a few days, which the course of disease is 7 to 10 days. In very few cases, there may be aseptic meningitis, encephalitis, myocarditis, pericarditis, pneumonia, paralysis and other complications, which is commonly known as "Enteroviruses Infection with Severe Complications."