Haemorrhagic stroke

Some strokes are due to bleeding in or around the brain. These are called haemorrhagic strokes.
Although they are not as common, this kind of stroke can be much more serious than ischaemic strokes, which are caused by a blockage.


A haemorrhagic stroke can happen when an artery inside your brain bursts causing bleeding within your brain. This known as an intracerebral haemorrhage .
It can also happen because of bleeding on the surface of your brain. Your brain sits inside a cushion of membranes that protect it from your skull.
Between the layers of membrane is a space, which is filled with fluid. If blood vessels near the surface of the brain burst, blood can leak into this space. This known as a subarchnoid haemorrhage.
Some of the things that can cause bleeding in and within your brain include:
  • High blood pressure is the main cause of all strokes. High blood pressure weakens the arteries and makes them more likely to tear. 
  • Cerebral amyloid angiopathy is a condition where a protein called amyloid builds up inside the blood vessels in the brain. This causes damage and makes your blood vessels more likely to tear. This condition is more common among older people.
  • An aneurysm is a weak spot on an artery, where the walls have become thin and weak because they have been stretched. This means that they can easily burst, especially if you have high blood pressure. Some aneurysms are present from birth, but things like smoking, using cocaine and some medical conditions can also make them more likely to develop.
  • Anticoagulant medication helps to prevent your blood from clotting. If you have an irregular heartbeat (known as atrial fibrillation) it’s likely that you will be given this type of medication to help reduce your risk of stroke. However, if it is not carefully monitored it can sometimes cause bleeding. 
  • Drugs, such as cocaine, can irritate blood vessel walls making them weaker and more likely to rupture.


A stroke is a medical emergency and if you have one you need to call 999 immediately.
The quicker your stroke is diagnosed and treated, the better your recovery will be.
Doctors will usually diagnose your stroke using a brain scan: either a computed tomography (CT) scan or a magnetic resonance imaging (MRI) scan. The scan will show whether your stroke has been caused by bleeding or by something else.
If you have a subarchnoid haemorrhage then your doctors may carry out a lumbar puncture as well as a brain scan. To do this they remove a small amount of the fluid that sits around your brain and spinal cord, to see if any blood has leaked into it.


If you have a haemorrhagic stroke you may need surgery to stop the bleeding, remove blood or relieve any pressure that has built up around your brain.
This is usually done with an operation called a craniotomy. This is when a surgeon cuts away a small piece of your skull so that he or she can get to your brain and the cause of the bleeding.
If your stroke was caused by a burst aneurysm, an operation may be needed to seal it and stop it bleeding again.
You may be given medication to lower your blood pressure or if your bleed was caused by anticoagulant medication, you will usually be given another drug to reverse the effects as soon as possible.

Find out more

There’s much more information about causes of haemorrhagic stroke and how it is treated in our leaflet Bleeding in the brain – haemorrhagic stroke


Page published: February 2015. To be reviewed: November 2015.Information Standard logo