The difference between severe and mild HFMD lies in the symptoms, test results, and treatment modalities. 1. Symptoms: symptoms of mild disease include fever, herpes, which may be accompanied by cough, runny nose, lack of appetite, etc. Symptoms of severe disease, in addition to symptoms of mild disease, may also include neurological symptoms such as lethargy, coma, oculomotor disorders, convulsions, respiratory symptoms such as respiratory distress, cyanosis, coughing up sputum, circulatory symptoms such as abnormal changes in blood pressure and cold extremities. 2. Examination results: the examination results of patients with mild hand-foot-mouth disease are usually mildly abnormal or within the normal range; the white blood cell counts of patients with severe disease are obviously elevated or significantly reduced, troponin and blood glucose are elevated; there can be respiratory acidosis, metabolic acidosis and other abnormalities of blood gas analysis. 3. Treatment: Treatment for mild cases mainly includes isolation and the use of broad-spectrum antiviral drugs such as ganciclovir, etc. In addition to the above treatments, patients with severe cases also need to use mannitol to reduce intracranial pressure for neurological symptoms, and mechanical ventilation for respiratory symptoms. If you are suffering from HFMD, you should seek medical treatment in a timely manner, and the relevant drugs should be used under the guidance of a doctor.