Bacterial meningitis is an acute infectious disease of the central nervous system caused by bacteria. The disease is usually acute or subacute, and the patients mostly present with headache, stiffness in the neck, fever, while impaired consciousness is rare. There are different clinical manifestations in various age groups, as follows: 1. Newborns and infants: the main manifestations are non-specific symptoms, such as lethargy, irritability, nervousness, anorexia, hypotonia, apnea, jaundice, diarrhea, generalized weakness and so on. Fever and hypothermia are common but infrequent; 2. Child patients: symptoms may appear within a few hours to a day, and are characterized by fever, severe headache, lethargy, irritability, confusion, photophobia, nausea, vomiting, stiffness of the neck and back pain; 3. Adults: symptoms are similar to those seen in children, and are typified by headache, stiffness of the neck, fever, and altered mental status. Studies have shown that only 41% of people have all of these symptoms. Patients who have been treated with painkillers and glucocorticoids may not have neck stiffness. 4. Elderly people over 65 years of age: Atypical presentations may occur, with fever, headache, and neck stiffness infrequently present, and confusion common. In addition to the typical symptoms, some patients will have certain concomitant symptoms, such as seizures in 15%-34% of newborns and infants, and hydrocephalus in 5% of patients. Seizures precede emergency room visits in 20% of pediatric patients, and may be accompanied by localized manifestations of neurological deficits in adults. A small percentage have bacterial meningitis caused by Neisseria meningitidis or pneumococcus, which may be accompanied by a rash.