Headache, fever and vomiting are mainly considered for the following reasons: 1. To be considered is caused by upper respiratory tract infection or gastrointestinal cold, in this case may be due to the hot weather, the patient ate some unclean food, resulting in acute gastroenteritis, the patient will have headache, fever, accompanied by obvious nausea, vomiting. And in the bacterial cold, bacteria, viruses will secrete some toxins, for the brain fascia will have stimulation, will also cause headache, fever, vomiting symptoms; 2, the patient in the summer, the pre-stroke will also have headache and fever, accompanied by obvious nausea, vomiting, the patient will also have the symptoms of dehydration exist; 3, to consider is some serious diseases, if the patient headache, fever, vomiting, accompanied by neck tonic and blurred consciousness, it should be considered as a central nervous system infectious disease.