A subarachnoid haemorrhage is a medical emergency. A CT scan is carried out urgently on anyone with a suspected bleed. A lumbar puncture may also be done. This involves extracting a small amount of the cerebrospinal fluid from the base of the spine. The presence of blood in the CSF suggests a subarachnoid haemorrhage.

All patients with a suspected subarachnoid haemorrhage are referred to a neurosurgeon. If the CT scan results do not confirm the diagnosis, a CT angiogram or digital subtraction angiogram may then be performed. Decisions are then made on the exact course of drug treatment that is likely to be most effective in each particular case:

  • It is normal to be advised to have complete bed rest to avoid changes in blood pressure, and to be given medication to avoid straining when having a bowel movement.
  • Some people just need medication to control pain, vomiting, or seizures.
  • Anti-hypertensive drugs such as nicardipine can reduce high blood pressure, so reducing the risk of further bleeds.
  • Nimodipine can be used to control vasospasms and to reduce the risk of stroke.
  • Mannitol can be used to reduce pressure inside the brain.

In cases where imaging techniques reveal an obvious abnormality, surgical treatment can reduce the risk of further bleeding and two types of surgery are possible:

  • A craniotomy involves opening the skull so that the surgeon can clip or remove the aneurysm.
  • Endovascular coiling involves passing a platinum coil through a blood vessel in the groin until it reaches the aneurysm in the brain. Putting this coil inside the aneurysm prevents blood flowing into it and prevents further bleeding.

Around 90% of people who have a subarachnoid haemorrhage develop hydrocephalus, fluid on the brain. One in 10 of these will require permanent treatment to relieve that pressure.