A stroke due to bleeding in or around the brain is known as a haemorrhagic stroke. This guide explains the different types of stroke caused by bleeding, and how they are diagnosed and treated.

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What is a haemorrhagic stroke?

If blood leaks from a blood vessel in or around the brain, this is called a haemorrhagic stroke. You may also hear it called a brain haemorrhage or a brain bleed.

In the UK, around 15% of strokes are haemorrhagic (due to a bleed), and about 85% are ischaemic (due to a blockage to the blood supply in the brain).

Haemorrhagic stroke tends to affect younger people than ischaemic stroke, and is most common in people aged between 45 and 70. Most strokes in the UK happen over the age of 70.

There are two main types of haemorrhagic stroke:

  • Bleeding within the brain: called an intracerebral haemorrhage, or intracranial haemorrhage (ICH).
  • Bleeding on the surface of the brain: called a subarachnoid haemorrhage (SAH).

Bleeding within the brain (intracebral haemorrhage or ICH)

When an artery inside the brain bursts it's called an intracerebral haemorrhage. About 10% of all strokes are of this type. 

The blood leaks out into the brain tissue at high pressure, killing brain cells and causing brain swelling.

Bleeding on the surface of the brain (subarachnoid haemorrhage, or SAH)

The brain sits inside a fluid-filled cushion of membranes that protects it from the skull, called the subarachnoid space. If blood vessels near the surface of the brain burst and blood leaks into the subarachnoid space, this is called a subarachnoid haemorrhage (SAH).

SAH accounts for around 5% of all strokes, and it is most often caused by a burst aneurysm (a bulging of the wall of an artery).

Subarachnoid haemorrhage (SAH) can run in families. If you have had an SAH and are concerned that this might affect your own family, speak to your GP. They can help you understand the causes of your stroke and the risks for your family members. 


Some people get a sudden, severe headache, or a very stiff neck with vomiting during a haemorrhagic stroke. But the main signs of a haemorrhagic stroke can be any of those in the FAST test.

The FAST test helps to spot the three most common symptoms of stroke. But there are other signs that you should always take seriously. These include:

  • Sudden weakness or numbness on one side of the body, including legs, hands or feet.
  • Difficulty finding words or speaking in clear sentences.
  • Sudden blurred vision or loss of sight in one or both eyes.
  • Sudden memory loss or confusion, and dizziness or a sudden fall.
  • A sudden, severe headache. If you spot any of these signs of a stroke, don’t wait. Call 999 straight away. 

What causes a haemorrhagic stroke?

High blood pressure

The main cause of haemorrhagic stroke is damage to the very small arteries inside the brain, which is often related to high blood pressure (hypertension). 

This process, called ’small vessel disease’, makes the small arteries in the brain more prone to bleeding. 

Cerebral amyloid angiopathy (CAA)

This is a common type of small vessel disease where a protein called amyloid builds up inside the small blood vessels near the surface of the brain. The resulting damage can cause a vessel to tear, causing bleeding.

This condition is more common among older people, and older people with dementia. Although there are no proven treatments for CAA, controlling blood pressure can help reduce the risk of bleeding in the brain.

Magnetic resonance imaging (MRI) scans have shown that CAA is present in patients with bleeds in specific areas of the brain near to the surface (called lobar areas), known as lobar intracerebral haemorrhage. Smaller bleeds, which can be detected on MRI scans, are called “microbleeds”. Microbleeds are a common feature of CAA and often appear without symptoms.

Burst aneurysm

An aneurysm is a weak spot on an artery that has ballooned out. Artery walls are usually thick and strong, but the walls of an aneurysm are thin and weak because they have been stretched. Aneurysms most commonly occur in the main artery leading away from the heart (the abdominal aorta), and the brain.

Some brain aneurysms are present from birth. There are also a number of risk factors that increase your chances of developing a brain aneurysm. These include smoking, high blood pressure, a family history of aneurysms, using cocaine, and having a genetic kidney condition called autosomal dominant polycystic kidney disease (ADPKD).

A brain aneurysm doesn’t usually cause any symptoms unless it bursts, but people may experience pain on one side of the face or around an eye, loss of vision or headaches.

A burst aneurysm is the most common cause of a subarachnoid haemorrhage. After a haemorrhage an aneurysm can seal itself, but there is a risk of it bleeding again. 

Abnormal blood vessels

Rarely, people are born with abnormalities in their blood vessels. They are called vascular malformations, and are tangles of blood vessels or enlarged blood vessels.

Cavernous malformation is one type of vascular malformation. It's a cluster of enlarged blood vessels. Many people with this condition do not experience any ill effects, but if the thin vessel walls break it can cause bleeding in the brain. 

Blood-thinning medication

Medication to lower the risk of blood clots causes a higher risk of bleeding in the brain. However, your risk of stroke is carefully monitored when you’re taking blood-thinning medications, including antiplatelet agents and anticoagulants.

People using these types of drug have their suitability assessed by a doctor, who looks carefully at the benefits of the blood-thinning medication and the risks of bleeding. You should always discuss any concerns about your medication with your doctor.

Illegal drugs

Cocaine can raise the risk of a haemorrhagic stroke in the days after using it. Others, like cannabis and khat, are associated with an increased risk and higher death rate from stroke. 

How are strokes due to bleeding diagnosed?

When someone is taken to hospital with a suspected stroke, a brain scan should be carried out urgently and within one hour of arriving in hospital. The scan could be either a computed tomography (CT) or MRI scan. The brain scan will show if a stroke has happened, and whether it was caused by a blockage or by bleeding.

To help diagnose SAH, a lumbar puncture might be carried out as well as a brain scan. This is a procedure to remove a sample of the cerebrospinal fluid that bathes the brain and spinal cord. It will show if any blood has leaked into this fluid.

A digital subtraction angiogram (or catheter angiogram) uses X-rays to locate the burst blood vessel. A fine tube called a catheter is put into an artery, usually in the groin. A liquid called a contrast, or dye, is injected into the blood. The contrast makes the blood vessels show up on an X ray and reveals where the bleeding occurred.

To help diagnose the cause of intracerebral haemorrhage you might also have further CT or MRI scans, including special scans of the blood vessels that do not require a catheter (non-invasive angiography). 

How will I be treated?


When admitted to hospital with a brain haemorrhage, if you're taking anticoagulants, you will be immediately prescribed medication to reverse those effects. If you're also diagnosed with high blood pressure, you will be given medication to bring it down.

After an SAH a lack of blood supply to the brain can lead to further brain damage, called cerebral ischaema. To prevent this, you may be given a drug called nimodipine for about three weeks.

Pain relief

Morphine or paracetamol with codeine may be given to you to help with the severe headache associated with an SAH.


Some people develop epilepsy after a haemorrhagic stroke. There is a range of different type of medication you may be given to treat it. 

See our page ‘Seizures and epilepsy after stroke’ for more information.  

Surgery to relieve pressure on the brain

Emergency surgery is sometimes needed to remove blood, to relieve any pressure that has built up, or to repair the blood vessels. This is usually done with a procedure called a craniotomy. This operation should be carried out by a neurosurgeon.

During the operation, a small piece of skull is cut away so the surgeon can access the cause of the bleeding. They can then repair any damaged blood vessels and ensure there are no blood clots that could restrict the flow of blood in your brain. If a blood clot has formed, it may be removed. After the bleeding has stopped, the piece of skull can be replaced.

With any type of bleed in or around the brain, the escaping blood can sometimes alter the normal flow of cerebrospinal fluid. This can result in a build-up of fluid around the brain called hydrocephalus. This can cause pressure and pain, and if left untreated, can cause damage to the brainstem (the base of the brain which controls most of the automatic functions that keep us alive, such as breathing). 

Treatments include a lumbar puncture or surgery to drain away the excess fluid. This is carried out using a shunt (a thin tube temporarily implanted into the brain). 

Surgery to seal an aneurysm

If your stroke was caused by a burst aneurysm, an operation may be necessary to seal it and stop it bleeding again.

During coiling a fine tube is inserted into an artery in the groin and carefully steered up to the aneurysm near the brain. X-rays are used to guide the tube. On the tip of the tube is a platinum coil, which is released into the aneurysm.

More than one coil is usually inserted. Once the aneurysm is full of coils, blood cannot enter it, sealing it off and preventing future rupture. Clipping involves opening the skull and making an incision in the membranes that protect the brain to get to the aneurysm. The surgeon will then put a clip around the base of the aneurysm to seal it shut.

The type of procedure used depends on your health and the aneurysm’s position. When either is used, recovery time and length of hospital stay depend on the severity of the rupture.  

Recovering from a haemorrhagic stroke

It's quite common for people to experience headaches after any type of bleeding in the brain. This may be due to swelling or changes in the levels of cerebrospinal fluid. The pain tends to lessen over time and can usually be controlled by painkillers such as paracetamol. You should not take aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, as they can increase the risk of bleeding.

Drinking plenty of water and avoiding caffeine and alcohol can help to reduce these headaches. If you have another severe headache or a persistent headache, seek medical attention urgently.

Some people report strange sensations in their brain after an SAH, like running water or a tickling feeling on their brain. These are quite common and usually pass in time.  

Effects of a stroke

The effects of a stroke are unique to each individual, and recovering from a stroke is different for each person. A stroke may cause a range of physical and communication difficulties including difficulty walking, slurred speech, cognitive (memory and thinking) problems, incontinence and vision problems.

You may need rehabilitation, like physiotherapy and speech and language therapy. Rehabilitation should begin soon after the stroke, and it can help you make the best recovery possible for you.

Your recovery after stroke, and your medical and therapy needs, should be assessed after you are discharged from the hospital. You can read more about the physical and emotional effects of stroke on our website and in our guide ‘Next steps after a stroke’. You can find details of other sources of help and support in the ‘Where to get help and information' section of this guide.


By law, you must not drive for a month after a stroke or transient ischaemic attack (TIA). You might need to tell the DVLA (or DVA if you are in Northern Ireland) about your stroke. If you had a subarachnoid haemorrhage (SAH), you must inform the DVLA/DVA. Depending on what kind of stroke you had and the kind of driving licence you hold, you might not be able to drive for a longer period or may have to stop driving. To find out more, visit our page Driving after a stroke.  

Reducing your risk of another stroke

You should be given advice about other ways of reducing your risk of a stroke. Stopping smoking, reducing your blood pressure, and losing weight can help to reduce your risk of a stroke.

You should have your blood pressure checked regularly after a bleed in the brain, as high blood pressure is an important cause of another brain haemorrhage. If you were taking blood-thinning medications these should be reviewed by your doctor to decide whether they should be stopped, continued, or changed.