Whether intracranial aneurysm 30 years is dangerous or not cannot be generalized, it is mainly related to the size of intracranial aneurysm, whether there are symptoms and whether the aneurysm is bleeding or not. 1. If the intracranial aneurysm is small, and the patient does not have headache, dizziness, nausea, vomiting and other signs of increased intracranial pressure, it can be observed first, and regular review of cranial MRA or CTA can be done, the danger of such a case is relatively small, but it should also be taken seriously. 2. If the intracranial aneurysm is large, or the patient has cranial nerve compression or increased intracranial pressure, manifesting headache, dizziness, nausea, vomiting and dysfunction, or the aneurysm ruptures and bleeds, then the condition is more serious, and timely treatment is needed. If not treated in time, the patient’s life may be in danger. It is recommended that patients seek timely medical treatment to prevent rupture of intracranial aneurysms, and do not be negligent to avoid delaying the condition.