What is a lumbar puncture? It is a lumbar puncture, which is an important and commonly used operative test for the diagnosis of neurological diseases. It is mainly used for the diagnosis of inflammatory diseases of the central nervous system, infectious diseases, arachnoid hemorrhage, vasculitis of the central nervous system and intracranial tumors. Lumbar puncture is also useful in the diagnosis of spinal cord lesions and radiculopathies (such as Guillain-Barré syndrome). Is lumbar puncture safe? In the absence of contraindications, lumbar puncture is a very safe test. Since the amount of cerebrospinal fluid produced by secretion is about 500 ml per day, if about 10 ml of cerebrospinal fluid is taken in one lumbar puncture, it can be produced and replenished within 30 minutes. A small number of patients have a transient headache after lumbar puncture – post-lumbar puncture hypocranial pressure headache, which usually lasts 1-2 days. The headache is mainly in the frontal and occipital areas, and may be accompanied by neck and back pain, and the symptoms are aggravated when coughing or standing, and may be accompanied by nausea, vomiting and tinnitus in severe cases. Usually, low cranial pressure headache after lumbar puncture can be relieved quickly by resting flat on the back and drinking plenty of water. What conditions should not be treated with lumbar puncture? Lumbar puncture should not be performed for significant occupying lesions in the posterior cranial fossa, such as large tumors, infections at the puncture site, hematologic disorders with a tendency to bleed, and those with significantly reduced platelets.