There is a folk song that goes like this: “Big head, big head, no worries about rain, people have umbrellas, I have a big head”; the cartoon “Big Head Son and Little Head Dad” is also very popular with children. But if you really have a big-headed doll at home, you need to be alert to hydrocephalus. How can we know that a big head is abnormal? First, let’s understand the pathogenesis of hydrocephalus. ”Hydrocephalus is an excessive accumulation of cerebrospinal fluid in the skull due to various causes of excessive secretion of cerebrospinal fluid and impaired circulation or absorption. A common example is the sink at home, there are two kinds of water in the sink may cause more and more water: 1, the water release faucet water is too large, too much, too fast. 2, the water out of the pipe is too slow, too little, too small. When the pool inside the water accumulates to a certain level will produce a series of problems. Hydrocephalus is both similar. When the cerebrospinal fluid inside the head accumulates to a certain level, the cranial pressure increases, and the baby’s head circumference begins to increase, faster than normal, because the baby’s skull sutures have not yet closed, and the baby becomes a “big head doll”. The cerebrospinal fluid inside the head continues to accumulate and the pressure continues to increase, compressing the oculogyric nerve, so that the eyes droop and the sun goes down, i.e. the “sunset sign”. ”The causes of hydrocephalus are complex and varied: intrauterine infections, vascular lesions, folic acid deficiency and other factors that lead to malformations in the development of the nervous system; genetic factors and other factors such as intracranial tumors or ventricular hemorrhage. The diagnosis of hydrocephalus is becoming easier with the innovation of medical diagnostic techniques. Many children can be detected early before birth through ultrasound or other imaging techniques. ”Hydrocephalus is not an incurable disease. The more established surgical procedures are ventriculoperitoneal shunts and tricortical fistulas. Ventriculoperitoneal shunts are used for all causes of hydrocephalus. Triventriculostomy is more commonly used for obstructive hydrocephalus. The secondary neurological impairment caused by hydrocephalus can be significantly improved by the correction of hydrocephalus.