An intracranial aneurysm is a bulge or ballooning in a blood vessel in the brain. This occurs when the vessel wall weakens, leading to a risk of rupture. If an aneurysm bursts, it can cause a subarachnoid hemorrhage, which is a type of stroke that can be life-threatening. Symptoms of an intracranial aneurysm may include severe headaches, vision changes, or neck pain. Diagnosis is typically done through imaging techniques like CT scans or MRI. Treatment options may involve monitoring, medication, or surgical procedures to prevent rupture and manage symptoms.