A subarachnoid haemorrhage is a serious and potentially life-threatening condition where blood leaks out of blood vessels over the surface of the brain.
This bleeding is caused by either traumatic injury or a stroke (for more information, see the Causes page and Health A-Z: stroke).
It is known as a subarachnoid haemorrhage because the bleeding occurs in the arteries that run underneath a membrane in our brain called the arachnoid, which is just below the surface of the skull.
During a subarachnoid haemorrhage, the blood damages the brain tissue. The reduction of blood supply can also cause further brain damage, leading to disruption or loss of brain function and possibly death.
A subarachnoid haemorrhage is serious
Every year around 8,000 people in the UK have a subarachnoid haemorrhage. It is more common in middle-aged people, and women are more likely to be affected than men.
A subarachnoid haemorrhage is a serious condition, and 50% of people who experience it will be left severely disabled or die. However, the prospects of recovery are good if the patient survives the initial bleeding and they are transferred quickly to a specialist neurosurgical unit (a medical unit that specialises in treating conditions of the brain and nervous system).
A number of surgical techniques have proved successful in treating subarachnoid haemorrhages. Following treatment, a long period of rehabilitation will be necessary.
If you have a subarachnoid haemorrhage, it may have implications for driving. See Complications for more information and advice about driving following a subarachnoid haemorrhage.
The Useful links section provides details about how to inform the DVLA about medical conditons.
