In children with high lactate dehydrogenase, if it is mildly elevated without discomfort, observe at home for the time being. If the elevation is obvious with discomfort, it is mostly considered to be caused by damage to cardiomyocytes, liver cells, or muscle-related diseases, so it is recommended to go to the hospital for re-examination, and the doctor will combine other tests and clinical symptoms for treatment. Common causes and treatment 1, myocardial cell damage: such as viral myocarditis, toxic myocarditis and other diseases, will to a certain extent cause myocardial cell damage, mostly manifested as chest tightness, palpitations, dyspnea, fatigue and other symptoms. Need to improve myocardial enzymes, electrocardiogram, cardiac ultrasound and other examinations, under the guidance of doctors to apply drugs that nourish the heart muscle, such as creatine phosphate, 1,6-diphosphate fructose, etc., can also apply interferon for antiviral drug therapy, if necessary, surgical treatment; 2, liver cell damage: hepatitis, liver tumors and other damage to liver function, can be manifested as abdominal pain, nausea, vomiting, anorexia and other discomfort, liver function tests will also indicate abnormal. Need to follow medical advice for liver protection treatment, such as inosine tablets. Hepatitis can be treated with glycyrrhizic acid preparations for liver protection, and antifibrotic treatment with drugs such as Anluo Fibrillation Pill; liver tumors need to be treated with timely surgery, combined with radiotherapy if necessary; 3. Muscle-related diseases: such as rhabdomyolysis syndrome, which can manifest as muscle pain, muscle weakness, deepening of urine color and other symptoms, need to improve urine routine and sediment microscopy, kidney function, muscle enzyme level examination. The treatment needs to eliminate the cause, to drug therapy, such as the application of sodium bicarbonate, in serious cases need to be surgical treatment. Attention usually need more rest, early to bed and early to rise; maintain a calm, happy state of mind, more outdoor activities; appropriate exercise to improve the ability to resist disease; daily life more attention to their own health, if there is discomfort, need to immediately inform parents, timely medical treatment.