Headache caused by fever mainly includes the following causes: 1. Fever itself can cause vasodilatation leading to headache, fever can lead to vasodilatation of the whole body and cause lack of oxygen in the brain can also lead to headache; 2. Fever causes are mostly caused by some viral or bacterial infections, and inflammatory mediators in the acute stage can lead to headache in patients, and attention needs to be paid if the patient has a severe headache accompanied by nausea and vomiting, or if the fever If the headache is severe, accompanied by nausea and vomiting, or if the headache does not subside after the fever subsides, the possibility of intracranial infection should be excluded and the patient should be seen by a specialist hospital. If the fever is physical, the headache will be relieved after the temperature is lowered, and the headache can be considered to be related to the fever. Because many of them are caused by viral or bacterial infections, anti-infection treatment may also be required for the cause of the disease, and the headache will be relieved after the condition improves. If the headache and fever are accompanied by nausea, vomiting and severe headache, it is necessary to pay attention to the possibility of intracranial infection and to seek medical attention in time to exclude more dangerous cases.