An intracranial aneurysm is a cerebral angiomatous protrusion that arises from abnormal changes in the local blood vessels and is not a tumor per se. Such protrusions are often caused by abnormalities in the structure of the vessel wall. The middle layer of intracranial arterial wall lacks elastic fibers and smooth muscle, and there is a lack of supporting structures around the blood vessels. Under the impact of high-pressure blood flow, aneurysm-like protrusions, i.e., aneurysms, are gradually formed in the bifurcation of the blood vessels and other weak areas. Intracranial aneurysm is common in middle-aged people, and it ranks the third among patients with cerebrovascular accidents, second only to cerebral thrombosis and hypertensive cerebral hemorrhage. The danger of intracranial aneurysm is that its rupture often leads to disability or death of patients, and survivors can still bleed again. Therefore, early detection, early diagnosis and early treatment are extremely important in the diagnosis and treatment of intracranial aneurysms. Intracranial aneurysms are often difficult to detect, and clinically unruptured aneurysms are often asymptomatic unless they are detected by special cerebral angiography, so their onset is hidden. Patients with intracranial aneurysms often present to the emergency room with severe symptoms caused by rupture of the aneurysm. The onset of symptoms is often preceded by blood pressure fluctuations associated with exercise, emotional stress, defecation, and trauma. Clinical manifestations caused by ruptured aneurysms can be divided into two main categories – ruptured aneurysm bleeding symptoms and focal symptoms. Ruptured aneurysm hemorrhage symptoms are often manifested as severe subarachnoid hemorrhage, with severe headache, which is often described as a “cracking headache”, accompanied by nausea, frequent vomiting, stiff neck, and profuse sweating. Those who bleed a lot often suffer from impaired consciousness or even coma. Subarachnoid hemorrhage caused by aneurysm can lead to extensive cerebral vasospasm, and then cause cerebral ischemia and cerebral infarction, and the patient may have hemiparesis, aphasia, sensory impairment, and even coma. After rupture of aneurysm, bleeding can be stopped by thrombus formation at the breach. However, the local thrombus is often easy to dissolve within 2 weeks after the first bleeding, so it may rupture and bleed again. Re-rupture of the aneurysm often leads to disability and death, making it extremely difficult to save the patient. The focal symptoms of ruptured intracranial aneurysms depend on the location of the aneurysm, the adjacent anatomy, and the size of the aneurysm. The most common manifestation is motor nerve palsy, which is commonly seen in internal carotid artery – posterior communicating artery aneurysm and aneurysm of posterior cerebral artery, manifesting as unilateral eyelid ptosis, pupil dilatation, inability to inwardly, upwardly and downwardly vision, and disappearance of direct and indirect light reaction. Sometimes there are focal aura symptoms before aneurysm rupture and hemorrhage, such as mild migraine, orbital pain, followed by paresthesia of the motor nerve, which should be alerted to the ensuing subarachnoid hemorrhage. Aneurysm hemorrhage of middle cerebral artery, such as the formation of hematoma; or other parts of the aneurysm hemorrhage, cerebral vasospasm cerebral infarction, the patient may appear hemiplegia, or aphasia. Giant aneurysms can also cause impaired vision and visual field. When the above symptoms occur, the possibility of intracranial aneurysm should be considered. Diagnosis requires cerebral angiography (DSA), but DSA is invasive and relatively risky. Therefore, CT angiography (CTA) is commonly used for screening, which is convenient, fast, less traumatic and has a strong stereoscopic image. However, CTA requires high-performance CT equipment, generally requiring more than 64 rows of CT machines, thus limiting the screening of intracranial aneurysms in primary hospitals. Therefore, once suspected of intracranial aneurysm, one should go to a large hospital with examination and treatment conditions in a timely manner to avoid delays. Intracranial aneurysm is like a ticking time bomb, and it is difficult to predict when it will rupture. Therefore, it is recommended to treat it aggressively, especially in the case of ruptured aneurysm. The treatment of intracranial aneurysms, like defusing a bomb, is technically demanding and risky, and should be carried out in large hospitals that are equipped to save lives. Currently, there are two main treatment methods – craniotomy to clip the aneurysm and percutaneous transluminal endovascular intervention to embolize the aneurysm. Craniotomy is highly invasive, but it is usually effective for aneurysm closure, and postoperative recurrence is minimal. Interventional embolization is less invasive, but the treatment is expensive and recurrence is still possible after surgery. In addition, the difficulty of surgery and embolization varies for different parts of the aneurysm, so the choice of treatment should be based on the location, morphology, size, and health economics of the aneurysm. Regardless of the modality, there is a possibility of aneurysm rupture during surgery, and in the event of aneurysm rupture during interventional embolization, it is often difficult for the patient to survive due to the difficulty in removing the hematoma in a short period of time by craniotomy. In addition, both have the risk of extensive cerebral vasospasm and cerebral infarction after the procedure. Intracranial aneurysms progress rapidly, and once an aneurysm ruptures, it is often extremely dangerous and worsens the condition. Patients with symptoms related to aneurysms should go to large hospitals with neurosurgery conditions in time to avoid delays. However, if treated in time, most of the patients can recover, and the disability and mortality rates are greatly reduced, which brings good news to the patients and their families.