Recently, many patients and friends have inquired about arachnoid cysts, and in this issue I will give you a popularization of intracranial arachnoid cysts. Intracranial arachnoid cyst is a non-neoplastic benign occupying lesion formed by the arachnoid membrane and the sac is filled with cerebrospinal fluid, which accounts for about 1-3% of intracranial occupying lesions, of which males are more common than females. Intracranial arachnoid cysts are classified as congenital or acquired, with congenital arachnoid cysts being the most common, often caused by the accumulation of cerebrospinal fluid during the embryonic period, resulting in abnormal development of the subarachnoid space, leading to the formation of poorly draining cysts. Acquired arachnoid cysts, on the other hand, are most often caused by birth injuries, postnatal intracranial hemorrhage, intracranial infections, and craniotomy injuries, which result in the accumulation of cerebrospinal fluid and the formation of cysts due to arachnoid adhesions. Most patients have epileptic seizures as the first symptom, while headache and vomiting are common clinical symptoms. In general, smaller arachnoid cysts do not have obvious clinical symptoms, and arachnoid cyst lesions can be detected clinically by CT or MRI of the head, but of course the symptoms of arachnoid cysts vary from site to site, so if you have frequent headaches or nausea or vomiting, then I suggest you better improve your head MRI examinations. If you have frequent headaches or nausea or vomiting, then I suggest that you should have an MRI of your head. The main concern of our patients is whether they need surgery for intracranial arachnoid cysts. For those patients with asymptomatic arachnoid cysts, they can be followed up with regular review to observe whether the arachnoid cyst has increased in size; while for patients with symptoms, they need to be evaluated for surgical indications, such as those with elevated intracranial pressure, significant brain compression, midline shift, and obstructive hydrocephalus are indications for surgery, while when the cyst is accompanied by intracranial hemorrhage, significant neurological dysfunction, epilepsy, etc., timely surgery is recommended treatment; for pediatric patients, if it is a temporal lobe cyst, the possibility of epilepsy is higher, and once found, surgical removal is recommended. The common surgical procedure we perform is cyst wall resection. The risk of this type of surgery is lower compared to brain tumor surgery and the prognosis is generally better, although there is a possibility of recurrence. Therefore, the need for surgery will depend on the specific situation of the patient friend.