Cerebrospinal fluid is a colorless, clear fluid found in the ventricles and subarachnoid space of normal people. The total amount of cerebrospinal fluid varies with age. 10-60 ml of cerebrospinal fluid is present in newborns, 60-90 ml in children, and 120-180 ml in adults. adult cerebrospinal fluid can produce about 800 ml per day and is renewed more rapidly. An acute increase in cerebrospinal fluid may indicate that the patient has hydrocephalus. In acute hydrocephalus, the patient may experience severe headache, nausea, vomiting, and seizures. If cerebrospinal fluid increases slowly, chronic hydrocephalus may develop. Chronic hydrocephalus can lead to symptoms such as cognitive decline, incontinence, and unsteadiness in walking. Mild hydrocephalus generally requires only conservative medication. If the condition is severe and conservative treatment is not effective surgical treatment, such as minimally invasive shunt, is required. When cerebrospinal fluid decreases, it may indicate cerebrospinal fluid leakage. Patients may have no abnormal symptoms, such as clear water from the nose, and some patients may experience dizziness, cognitive dysfunction, twitching of the limbs and foaming at the mouth, or even brain herniation in severe cases. Patients with reduced cerebrospinal fluid need bed rest, proper hydration, and timely compression of the leak hole after finding the cause to prevent further leakage of cerebrospinal fluid.