Hydrocephalus caused by saddle cyst surgery may be due to surgically induced infection, cerebrospinal fluid circulatory disorders, excessive cerebrospinal fluid secretion and other factors. 1. Surgery-induced infection: after saddle cyst surgery, it may be accompanied by intracranial infection, which leads to inflammatory reaction in the skull, resulting in adhesion of intracranial tissues, affecting the secretion and absorption of cerebrospinal fluid, thus causing hydrocephalus. 2. Obstruction of cerebrospinal fluid circulation: after saddle cyst surgery, a small amount of blood may enter the ventricular system, which may obstruct the flow of cerebrospinal fluid, thus triggering hydrocephalus. 3. Excessive secretion of cerebrospinal fluid: cerebrospinal fluid has a protective effect on the brain and can maintain the balance of intracranial pressure. If the cerebrospinal fluid is secreted too much and cannot be absorbed in time, hydrocephalus can be triggered, but it is rare in clinical practice. If hydrocephalus is caused by saddle cyst surgery, you should cooperate with your doctor to avoid discomfort.