Encephalitis is usually caused by viral or bacterial infections, and common types are BSE, tuberculous encephalitis, etc. In the early stages, patients may have symptoms similar to those of the common cold, such as fever and headache, which may be accompanied by vomiting, weakness, and depression. The typical early symptoms of encephalitis patients are fever and headache, both of which may occur simultaneously or sequentially. The patient’s body temperature usually rises rapidly within 1-2 days, mostly above 38.5°C, and may be higher than 40°C in severe cases. The headache is usually a full headache of a dull aching nature, which is progressively worse. Patients may have vomiting, malaise, and depression along with fever and headache, and vomiting is usually jet-like. Some patients with encephalitis have a history of antecedent infections, such as acute upper respiratory tract infections and acute diarrhea, and develop fever, headache, and vomiting after 1-2 weeks as the disease progresses. Encephalitis has an acute onset and progresses rapidly, from milder discomfort such as headache and fever to blurred consciousness and impaired consciousness, which may take only a few days, and death may even occur in severe cases. Therefore, it is recommended that patients with these manifestations seek medical attention promptly to avoid disease progression.