What Causes A Brain Haemorrhage?
- The Natalie Kate Moss Trust
- Oct 30, 2024
- 4 min read
A brain haemorrhage, or haemorrhagic stroke, is a medical emergency involving bleeding in or around the brain, which can damage brain cells and lead to severe consequences, including disability or death.
There are around 4.6 million cases of brain haemorrhages annually, but only 3 out of 5 people will survive one month after having a haemorrhagic stroke—a statistic that hasn't improved in over 40 years. To reduce these figures, it's essential to understand brain haemorrhage, their causes, risk factors, and brain haemorrhage prevention measures.
What are the two main types of Brain Haemorrhages?
INTRACEREBRAL HAEMORRHAGE (or ICH)
This is when there is bleeding within the brain: Blood leaks out of a blood vessel into the brain tissue, sometimes deep inside the brain. This is the most common type of haemorrhagic stroke. There are approximately 3.4 million cases of ICH every year. (Source: World Stroke Organisation)
SUBARACHNOID HAEMORRHAGE (or SAH)
This is when there is bleeding on the surface of the brain: Blood leaks out of a blood vessel on the surface of the brain, and gets between the layers of protective membranes that surround the brain, cushioning it from injury (the subarachnoid space). This is the least common type of stroke, and around 1/3 of all haemorrhagic strokes are SAH (about1/20 of all strokes). There are approximately 1.2 million cases of SAH every year. (Source: World Stroke Organisation)
Key Causes of Brain Haemorrhages
Brain haemorrhages can result from several underlying conditions:
Aneurysms
These are weak spots in blood vessels, which can bulge and eventually burst. While the exact reason aneurysms form is unclear, factors like smoking, hypertension, and family history heighten risk. Around 1 in 15,000 people have a ruptured brain aneurysm in England each year. Brain aneurysms can develop in anyone at any age, but are more common in people over the age of 40. Women tend to be affected more commonly than men. (Source: NHS England).
A brain aneurysm doesn't usually cause any symptoms unless it ruptures. But some people with unruptured aneurysms experience symptoms such as: sight problems, pain on one side of the face or around the eye, persistent headaches.
Arteriovenous Malformations (AVMs)
In an AVM, the blood vessels carrying blood to and from the brain grow together in a tangle, instead of linking to the full network of smaller blood vessels in the brain. An AVM can reduce blood flow and compress the surrounding brain tissue. Inside the AVM, blood flows at high pressure into weak blood vessels, which can sometimes lead to bleeding.
Cavernous malformation, or Cavernoma
A cavernoma is a cluster of enlarged blood vessels, often said to look like a raspberry. It is made up of a series of connected ‘bubbles’ or caverns, filled with blood. Often these don’t cause any symptoms, but the blood vessel walls can be weak, making a bleed more likely.
Cerebral Small Vessel Disease (CSVD)
CSVD is an umbrella term for a variety of conditions resulting from damage to small blood vessels in the brain. In most cases, CSVD is caused by the narrowing or obstruction of small blood vessels in the brain due to inflammation and/or a buildup of misfolded proteins called plaques. (Source: American Brain Foundation). High blood pressure is the leading cause of small vessel disease in the brain; over a long period, high blood pressure damages the blood vessels inside your brain, reducing blood flow to your brain cells and this can lead to blood leaking into the brain tissue, often deep inside the brain.
High Blood Pressure
Whilst there are many causes of Brain Haemorrhages, one of the leading causes, and the one that can be managed the most, is our blood pressure.
High blood pressure can cause damage to the blood vessels in the brain over time and therefore managing your blood pressure is immensely important to avoid risking such damage.
If there is any damage to the vessels in the brain (whether due to blood pressure or otherwise), or if an individual has any abnormalities within the blood vessels (e.g. an Aneurysm or AVM etc), they are more susceptible to a bleed and therefore if there is a large amount of pressure going into those vessels there is more likely to be a bleed.
On average a third of the population has high blood pressure, but 50% of those people are undiagnosed (Source: Stroke UK) and therefore at risk of a brain haemorrhage. If we can individually understand, check and manage our blood pressure better, we are able to significantly mitigate the risk of having a bleed on our brain.
Who Is at Risk?
While haemorrhages can occur at any age, the risk increases with age, especially for individuals over 45.
Lifestyle choices like smoking, high alcohol intake, lack of exercise, poor diet, and high stress all raise blood pressure, which in turn raises the risk of brain haemorrhages.
Genetics can also play a role; a family history of aneurysms or hypertension might make certain individuals more prone to brain bleeds. (Read more about ‘Are Brain Haemorrhages Hereditary’)
Prevention Strategies
Although not all brain haemorrhages are preventable, some lifestyle changes can reduce the likelihood:
Monitor Blood Pressure: Controlling blood pressure through medication, diet, and exercise is vital.
Limit Smoking and Alcohol: Both activities damage blood vessels, increasing the risk of rupture.
Healthy Lifestyle: Regular exercise, balanced diets low in saturated fats, and maintaining a healthy weight support cardiovascular health.
Reduce Stress: Chronic stress can elevate blood pressure, so stress management is crucial.
Early awareness and intervention are essential. If you experience symptoms like sudden severe headaches (often called "thunderclap headaches"), nausea, or vision problems, seek immediate medical attention. Recognising symptoms early can be lifesaving, as quick diagnosis and treatment are critical to survival and recovery. Better understand the warning signs of a brain haemorrhages.
Remember, Time Equals Brain.
