Lumbar puncture tests mainly measure cerebrospinal fluid pressure, cerebrospinal fluid properties and the number of cells in the cerebrospinal fluid. They are generally used to check the cerebrospinal fluid pressure in patients with infectious diseases, autoimmune diseases and cerebral hemorrhage, for example, cerebrospinal fluid pressure can be measured by lumbar puncture. Normal human cerebrospinal fluid pressure is usually 80-180 mmH2O, and if it exceeds this range, whether it is low or high cranial pressure, the cause should be looked for. Also, the properties of the cerebrospinal fluid can be checked. Cerebrospinal fluid is usually colorless and transparent, but if there is an infectious disease, the color will change and if there is blood, it will become pink or bloody. Then, based on the cerebrospinal fluid cell count, the differential diagnosis of meningitis, bacterial meningitis, and viral meningitis, which are infectious diseases, can be made, as well as the examination of autoimmune diseases such as globulin.