Subarachnoid Haemorrhage
Subarachnoid Haemorrhage:
At a Glance
What it is: A subarachnoid haemorrhage is a type of brain bleed where blood collects in the space between the brain and its thin outer covering (the subarachnoid space).
How it affects people: : It can cause sudden severe headache, vomiting, and neurological symptoms, and may be life-threatening.
Key concern: Often caused by a ruptured aneurysm, which requires emergency treatment.
Diagnosis: Usually confirmed with urgent CT scan or lumbar puncture.
Treatment options: Intensive medical care, surgical treatment for subarachnoid haemorrhage such as clipping or endovascular coiling, and ongoing monitoring.
Outlook: With rapid treatment by a specialist neurosurgeon, many patients recover, but long-term follow-up is often needed.
What is a Subarachnoid Haemorrhage?
A subarachnoid haemorrhage occurs when bleeding develops in the space between the brain and the thin tissues covering it. This space, called the subarachnoid space, normally contains cerebrospinal fluid (CSF) that cushions the brain and spinal cord. When blood enters, it can irritate the brain, raise pressure inside the skull, and interrupt blood flow.
It happens when one of the vessels in the brain ruptures, often due to an aneurysm. The most common cause is a ruptured brain aneurysm, but other blood vessel problems, head injuries, or clotting conditions can also lead to this type of haemorrhage.
Types of Subarachnoid Haemorrhage
Doctors classify subarachnoid haemorrhage into two main categories:
Traumatic subarachnoid haemorrhage (tSAH): The most common type, caused by head injury such as falls, accidents, or trauma. Severity varies, but monitoring is important.
Aneurysmal subarachnoid haemorrhage (aneurysmal SAH): Caused by a ruptured aneurysm in a brain artery.
Non-aneurysmal subarachnoid haemorrhage: The cause is believed to be due to a blood vessel abnormality or clotting problem. It is investigated in the same way as a aneurysmal subarachnoid haemorrhage, but sometimes the cause is never found.
Common signs and symptoms
Sudden, severe headache often described as the “worst headache of your life” or a thunderclap headache
Nausea and vomiting
Stiff neck
Sensitivity to light
Confusion or difficulty concentrating
Sudden vision problems
Subarachnoid Haemorrhage Symptoms
Emergency / red flag symptoms
Loss of consciousness
Seizures
Sudden weakness or paralysis
Trouble speaking or understanding speech
Call 999 immediately if these symptoms develop. A subarachnoid haemorrhage is a medical emergency.
Causes and Who Is at Risk
Causes of Subarachnoid Haemorrhage
Ruptured aneurysm (most common cause of a spontaneous subarachnoid haemorrage)
Head injuries
Arteriovenous malformations (AVMs) or other vascular malformations
Blood clotting disorders or use of anticoagulants
Health and Family Factors You Can’t Change
Age (most common between 40–60)
Family history of aneurysms or arteriovenous malformations
Inherited conditions affecting blood vessels
Reducing Your Risk
You cannot always prevent a subarachnoid haemorrhage, but you can reduce your risk by:
Controlling high blood pressure
Quitting smoking
Avoiding heavy alcohol use
Regular monitoring if you have a family history of aneurysms or vascular disease
Getting a Diagnosis
A diagnosis of subarachnoid haemorrhage is usually made in an emergency. Tests include:
CT scan: First-line test to detect bleeding.
Lumbar puncture: If CT is negative but suspicion remains, a lumbar puncture can detect blood in cerebrospinal fluid (CSF).
Angiography: Used to locate a ruptured aneurysm or vascular abnormality.
MRI scan: Sometimes used for further detail.
Early and accurate diagnosis is vital. Doctors stress that every minute counts, the sooner treatment begins, the better the outcome. Fast diagnosis and treatment are essential to reduce complications.
Treatment Options for a Subarachnoid Haemorrhage
Treatment depends on the cause, severity, and patient’s health.
Surgical Treatments
Options include clipping (placing a metal clip at the base of an aneurysm) or endovascular coiling (inserting tiny platinum coils inside the aneurysm to prevent further bleeding).
Intensive Medical Care
Patients are usually treated in an intensive care unit, with close monitoring of brain pressure and vital signs.
Supportive Medical Care
Medicines may control blood pressure, prevent seizures, and reduce the risk of vasospasm using drugs such as calcium channel blockers.
Not every patient will need open surgery. Mr Kailaya-Vasan, a neurovascular surgery specialist UK, works with neuroradiologists and neurologists to plan safe, effective care. He is recognised as one of the best neurosurgeons in London for brain haemorrhage, with advanced expertise in complex cranial surgery.
Living with a Subarachnoid Haemorrhage
Recovery depends on the severity of bleeding, the patient’s overall health, and the speed of treatment. Some people return to full independence, while others may need long-term support.
Rehabilitation may include:
Physiotherapy for movement and strength
Occupational therapy for daily activities
Speech and language therapy if communication is affected
Psychological support for anxiety, depression, or memory problems
Long-term follow-up is essential, as some patients are at risk of further aneurysms or complications.
Book a consultation with Mr Ahilan Kailaya-Vasan
Receive a clear diagnosis and a tailored treatment plan from a leading consultant neurosurgeon. Appointments are available at top London hospitals, with remote options for international patients.
Seeking a second opinion?
If you have already received a diagnosis elsewhere, Mr Kailaya-Vasan can provide an independent review of your scans and medical notes, and explain the safest and most effective next steps.
FAQs about Subarachnoid Haemorrhage
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It is bleeding into the space around the brain, usually from a ruptured aneurysm.
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Common symptoms include a sudden severe headache, nausea, vomiting, and neurological decline.
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With urgent CT scan, lumbar puncture, and angiography to identify the cause.
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They include intensive care monitoring, surgical treatments such as clipping or endovascular coiling, and supportive care.
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Recovery varies. Some people recover fully, while others may have long-term effects such as fatigue, memory problems, or difficulty concentrating.
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A subarachnoid haemorrhage is a specific type of haemorrhagic stroke caused by bleeding into the subarachnoid space.
If you have any further questions, please get in touch.