Hydrocephalus is a phenomenon in which cerebrospinal fluid accumulates in the ventricles and subarachnoid space due to excessive cerebrospinal fluid production or impaired absorption and circulation. Causes of hydrocephalus: The main causes of hydrocephalus include malformation of the midbrain aqueduct, fetal brain infection, neonatal and postnatal meningitis causing skull base adhesions, intracranial hemorrhage causing meningeal adhesions, and tumor compression causing obstruction of cerebrospinal fluid circulation or malabsorption. In addition, when the choroid plexus is hyperplastic or there is papilloma, increased secretion of cerebrospinal fluid may also cause hydrocephalus, but it is less common. Clinical manifestations of hydrocephalus: In hydrocephalus, the cerebrospinal fluid is constantly increasing in the ventricles of the brain, which directly causes an increase in intracerebroventricular pressure and eventually an increase in intracranial pressure; at the same time, the brain parenchyma is thinned, the gyrus is flattened, the sulcus becomes shallow, and clinical symptoms appear. Early clinical manifestations of hydrocephalus include increased head circumference or rapid growth, bulging fontanelle, separation of cranial sutures, and dilated scalp blood vessels in children. In addition, due to the increased pressure in the anterior cranial fossa, the eyes turn down and protrude outward, exposing the upper white sclera and making the child’s eyes look like “sunset”. In addition, the child may suffer from mental inactivity, drowsiness, restlessness, vomiting, frequent convulsions, paralysis, and difficulty walking. The danger of hydrocephalus: If hydrocephalus is not treated in time, it will affect the intellectual development of the child. If early detection and timely treatment, intelligence can still be restored to normal. Therefore, as parents of infants, we should observe carefully, and if we find that the child has the above symptoms, we should promptly ask the doctor to do ultrasound or CT examination to help confirm the diagnosis for early treatment. It is also necessary to prevent intracranial infection and intracranial hemorrhage, if suffering from intracranial infection or intracranial hemorrhage should be treated promptly and thoroughly to prevent hydrocephalus caused by meningeal adhesions.