When to contact a doctor
Call 108 for a sudden extremely severe headache, especially with collapse or a neurological change. Do not wait for a clinic visit or drive yourself when unwell. Fever with severe headache and neck stiffness also needs urgent emergency assessment. An aneurysm found incidentally on an earlier scan does not make a new severe headache safe to observe at home.
What you may notice
A headache that reaches extreme intensity suddenly, within seconds or minutes, is different from a familiar gradually building headache. It may accompany vomiting, neck stiffness, collapse, seizure or a new problem with speech, sight or strength. A first unusually severe headache needs attention even if it starts to improve.
Brain and an enlarged artery segment
What could cause it?
Bleeding around the brain from a ruptured aneurysm is one possibility. Other urgent causes include different types of brain bleeding, arterial injury or narrowing, venous clots and infection. Migraine is also possible, but cannot safely be assumed from the symptom alone. Emergency assessment and appropriately timed tests are needed.
How interventional radiology may help
If a bleeding aneurysm is confirmed, a neurovascular team may secure it with coiling or another suitable endovascular treatment, or with surgical clipping. The choice depends on its anatomy and the emergency findings. IR has no automatic role in an ordinary headache; diagnosing the cause comes before selecting a vessel treatment.
Further reading: detailed assessment and treatment options
Patient information sources
References are in English.
Educational information, not a diagnosis. The causes listed are examples, not a complete list. Tests and treatment depend on your individual assessment.