When a child is sick, parents are most worried. When is the most important time to take your child to the doctor has become a major concern for parents. According to pediatricians, 20% of common childhood illnesses require an emergency visit, 30% can wait until the second day to see a doctor, and 50% just need care at home. Doctors pointed out that these symptoms of common diseases should not be ignored. 1, high fever: If the child’s temperature is lower than 39 ℃, if the mental state, appetite, etc. are still good, parents should do is to closely observe, but this observation is not to stare at the thermometer, mainly to see the overall state of the child. However, if the child’s fever exceeds 40℃, or if the fever continues for more than two consecutive days, or if it is accompanied by other obvious discomfort, the child must be sent to the doctor within 48 hours. 2. Headache: Parents should first clarify whether their child has a real headache and the degree of it. If the headache is only mild, take rest. If it lasts for several hours, or if it affects his appetite, or even if his favorite TV program fails to interest him, it is never a lie to skip school, and he should go to the hospital immediately. If the headache is accompanied by confused thinking and blurred vision, it is mostly related to the nervous system; if it is accompanied by fever, vomiting, confusion or stiff neck, it may be combined with a serious infection, such as meningitis, to see the emergency room. 3, widespread rash: If the rash is red, the color becomes lighter or whiter after pressing with the finger, and the color can be restored after releasing the finger, most of them are viral rashes or allergic reactions, and there is usually no need to worry. If it does not change color after pressure, it may be a manifestation of a critical illness such as meningitis or sepsis, especially if accompanied by fever and other symptoms, and should be sent to a doctor immediately. In addition, if the rash is accompanied by lip or facial swelling, or when breathing is strained, this may be a serious allergic reaction that can be life-threatening. 4. Acute gastrointestinal disease: When a child has food poisoning or gastroenteritis, parents should closely monitor symptoms such as vomiting or diarrhea. Generally, vomiting 3 times in half a day rarely leads to dehydration, but if diarrhea occurs 8 times in 8 hours, or when there is both vomiting and diarrhea, dehydration will occur. Immediate medical attention is needed. 5, stiff neck: children appear stiff neck, difficult to turn, rarely caused by muscle pain, if accompanied by fever, photophobia, headache and other symptoms, most of them are suffering from meningitis, should immediately seek medical attention; if accompanied by fever, may be tonsillitis; if there is a history of trauma, it is mostly the performance of cranio-cerebral trauma, should also immediately seek medical attention.