Although the incidence of spontaneous intraventricular hemorrhage is low, the morbidity and mortality rate is extremely high. It is difficult to diagnose spontaneous intraventricular hemorrhage using clinical manifestations alone, and it may be misdiagnosed. Therefore, the use of laboratory tests or other ancillary tests to make the diagnosis is essential. The following are the tests to diagnose spontaneous intraventricular hemorrhage. 1. Laboratory tests (1) Routine blood tests The coagulation time and prothrombin time are higher than 1×10[sup]4[/sup]/mm[sup]3[/sup] in about 85% of cases, mainly with elevated multinucleated leukocytes. Leukocyte counts tend to be in the range of (1 to 2.5)×10[sup]4[/sup]/mm[sup]3[/sup], and pediatric patients may have decreased hemoglobin. Other routine items may not change significantly. The majority of patients have normal clotting time and prothrombin time. Only in patients with intraventricular hemorrhage due to coagulation disorders caused by leukemia, liver disease, hyperemesis gravidarum, and anticoagulation therapy do abnormalities occur, manifesting as prolonged clotting time and prothrombin time, but sometimes they are within the normal range. (2) Urine routine: Urine sugar and proteinuria are present. In cases of intraventricular hemorrhage due to abnormal coagulation or eclampsia, progressive hematuria may appear before and after the onset of the hemorrhage, suggesting the possibility of intraventricular hemorrhage. (3) Lumbar puncture examination The presence of bloody cerebral crest fluid, lumbar puncture pressure is more than 2.6 kPa (about 200 mmH2O) in most patients, and 3.3-6.7 kPa (250-500 mmH2O) in most patients. The ventricular pressure is 1-10kPa (80-800mmH2O). Erythrocytes and neutrophils were predominant in the cerebral crest fluid during the acute phase, and iron-containing heme phagocytes were seen 3 to 5 days after the disease, and bilirubinous macrophages were seen 7 to 10 days after the disease. However, this test should be performed cautiously in the acute phase to avoid inducing brain herniation. Lumbar puncture should be performed slowly, and the amount of fluid released should not exceed 8 drops/min and 7 ml. (1) Cranial plain film Secondary intraventricular hemorrhage caused by hemorrhage in the cerebral hemispheres, the pineal gland or choroid plexus calcified spots can be seen to be displaced to the opposite side. In cases of aneurysm, enlargement of the supraorbital fissure, thickening of the internal carotid artery, enlargement of the optic foramen and blurred margins are sometimes seen. Cerebral arteriovenous malformations can be seen with abnormal cranial vascular grooves and abnormal intracranial calcified spots. Patients with intracranial tumors may show signs of chronic intracranial pressure increase and sometimes localized cranial bone proliferation or destruction, which have certain reference value for the etiological diagnosis of spontaneous intracerebral hemorrhage. (2) Cerebral angiography can show the etiological manifestations of spontaneous intraventricular hemorrhage and the manifestations of hematoma in the brain parenchyma, in addition to the manifestations of hematoma breaking into the ventricles in fashion: the orthopantomogram can show the medial displacement of the lateral ductus arteriosus, and the distal pressure or straightening of its distal end; the anterior cerebral artery is still centered or the displacement is not obvious, and the internal cerebral vein is obviously displaced to the opposite side (more than 6 mm) and there is a “displacement separation” between the anterior cerebral artery. The phenomenon of “displacement separation” is characteristic of the hematoma breaking into the ventricle. Signs of enlargement of the lateral ventricle, i.e. spherical shape of the knee of the anterior cerebral artery and increased curvature of the pericallosal artery, larger venous angle, and straightening of the subventricular vein, are seen in lateral views. (3) CT scan is the safest, reliable, rapid and non-invasive means to diagnose intraventricular hemorrhage. Repeated examinations should be performed when necessary in order to observe the changes dynamically. Intraventricular hemorrhage may appear as a high-density intracerebroventricular shadow, or occasionally as an isointensity shadow. It can also detect the presence of rebleeding. (4) MRI scan The MRI manifestation of intraventricular hemorrhage is the same as that of cerebral hemorrhage. When there is meningeal irritation without cerebral localization signs or impairment of consciousness, or even cognitive dysfunction such as disorientation without other signs and symptoms, attention should be paid to whether spontaneous intraventricular hemorrhage has occurred, and the diagnosis can be made based on the results of laboratory and auxiliary examinations.