Encephalitis in 80 year olds can be cured with proper treatment. Treatment usually includes general treatment, medication, hyperbaric oxygen therapy and so on. If the lesion is more serious and the treatment is not timely, the prognosis may be poor and some sequelae may occur. 1. General treatment: adequate water intake should be ensured, and when there is an increase in body temperature, physical cooling should be used to maintain the body temperature at a constant level to avoid hyperthermia. 2. Drug treatment: when there is viral infection, antiviral drugs such as acyclovir and ganciclovir can be applied; when there is high fever, drugs such as ibuprofen can be applied to lower the body temperature; when there is increased intracranial pressure, mannitol can be applied for intravenous drip. 3. Hyperbaric oxygen therapy: it can correct the hypoxia of brain tissue, reduce the edema of brain cells, so as to lower the intracranial pressure and reduce the occurrence of sequelae. After the symptoms of encephalitis appear in the elderly, it is necessary to urgently consult a doctor for examination and treatment, and follow the doctor’s instructions for reasonable use of medication, so as to avoid the after-effects. Some patients have a better prognosis after timely treatment; some patients have a worse prognosis due to their poor condition and seriousness of the disease.