Subarachnoid Hemorrhage
Subarachnoid haemorrhage is bleeding into the space around the brain, most often caused by a ruptured aneurysm or significant head trauma.
When to get help quickly: It is a medical emergency. Any sudden severe headache different from normal headaches needs immediate hospital review.
Common symptoms
Sudden, severe headache (often described as 'the worst headache ever' or like being hit on the head), neck stiffness, vomiting, sensitivity to light, confusion, and sometimes loss of consciousness.
When imaging helps
Imaging confirms the bleed, shows where it is, often identifies the cause (aneurysm, AVM, or trauma), and guides treatment.
What radiology does
CT of the head is the fastest first test (very sensitive within the first 6 hours); CT angiography or catheter angiography identifies the source of bleeding.
What usually happens next
Treatment may include endovascular coiling or surgical clipping of an aneurysm, blood pressure control, and intensive care monitoring for complications such as rebleeding, vasospasm, and hydrocephalus.
Seen this on your report?
Your doctor or the radiologist who wrote it can tell you what it means for you.
Related scan guides
- CT Brain AngiographyA CT Brain Angiography (CTA Brain) creates detailed maps of the blood vessels inside your head. It uses X-rays and computer processing to capture clear, 3D images of your cerebral circulation.
- Transcranial Doppler ScanA transcranial Doppler (TCD) scan is a non-invasive ultrasound that measures the speed of blood flow through the blood vessels in your brain. It is commonly used to screen children with sickle cell anemia for stroke risk.