Subarachnoid Haemorrhage Care Staff Guide: Recognising a Brain Bleed

A subarachnoid haemorrhage is bleeding on the surface of the brain. The NHS describes it as a rare type of stroke and a life-threatening emergency that needs hospital treatment as soon as possible. It can happen suddenly, with little or no warning, and the first few minutes matter. Care staff who know the signs and act immediately can make a real difference to the outcome.

This guide summarises NHS information on subarachnoid haemorrhage, often shortened to SAH, and explains what care staff should look for, how to respond and how to support someone during recovery.

What causes a subarachnoid haemorrhage?

The NHS says the most common cause is a brain aneurysm: a bulge in a blood vessel in the brain that bursts and bleeds into the space around the brain. There is often no obvious reason for an aneurysm. Some people are born with one and others develop it later. A family history of brain aneurysms may increase the risk. Other causes include a severe head injury and an arteriovenous malformation, which is a problem with how blood vessels in the brain formed. The NHS adds that SAH can happen at any time, and may be more likely during activities such as coughing, using the toilet, lifting heavy objects or sex.

Symptoms

The NHS lists these symptoms:

• a sudden, extremely painful headache that does not go away, often called a "thunderclap headache"
• neck pain or stiffness
• nausea and vomiting
• sensitivity to light
• seizures (fits) or uncontrolled shaking
• fainting, drowsiness or confusion
• facial drooping, slurred speech or weakness on one side of the body

Because SAH is a type of stroke, it shares features with other strokes. Our guide to stroke recognition and the FAST test explains how to check for facial weakness, arm weakness and speech problems.

When to call 999

The NHS says to call 999 immediately if you or someone with you has any of the following: a sudden, extremely painful headache that does not go away; weakness or drooping on one side of the face, or difficulty smiling; weakness or numbness in one arm or one side of the body, or being unable to lift both arms and keep them there; speech problems, confusion or difficulty finding words; or blurred vision or loss of vision in one or both eyes. It adds that you should not drive yourself to A&E, and should follow the advice of the 999 call handler.

In a care setting this means:

• Do not wait to see if a severe headache settles. Call 999 and say clearly that you suspect a stroke or bleed on the brain.
• Note the time the symptoms started, as clinicians will need it.
• Stay with the person, keep them as comfortable as possible and follow the call handler's instructions.
• If the person has a seizure, follow the seizure plan and your first aid training. Our guide to epilepsy awareness and emergency seizure medicine covers this.
• Record what you observed and pass it to the ambulance crew.

Hospital treatment

The NHS explains that the main treatment is surgery to stop the bleeding. This may be neurosurgical clipping, in which a small piece of skull is removed and the aneurysm sealed with a small metal clip, or endovascular coiling, in which a thin tube is threaded through an artery in the groin or leg to the aneurysm and tiny metal coils are packed inside. Before and after surgery, medicines may be used to help with pain, lower blood pressure, prevent seizures or coughing, relieve nausea and soften stools. Hospital care is required from the outset.

Recovery and long-term effects

Recovery varies and can take months or years. The NHS says most people improve with treatment and some recover fully, but SAH can cause lasting mental and physical disability and affect quality of life. Possible effects include:

• seizures, and in a small number of people, epilepsy
• heart, lung or liver problems
• memory and concentration difficulties
• depression and mood changes
• fatigue
• unusual head sensations or headaches

Follow-up appointments check for complications, for other blood vessel problems or aneurysms, and for hydrocephalus, which is a build-up of fluid around the brain. Rehabilitation may include physiotherapy, speech and language therapy, cognitive behavioural therapy and cognitive exercises. The NHS also notes that advice is available on driving, work, exercise, travel and sex, and that some people need to stop working temporarily or permanently.

Supporting someone after an SAH

• Learn what the hospital team has said about triggers, activity limits and warning signs, and make sure these are in the care plan.
• Be patient with tiredness and with problems of memory or concentration. Break tasks down, repeat information kindly, and write things down. Our guide to post-stroke cognitive impairment screening may help you understand cognitive changes.
• Watch for low mood and anxiety and raise them with the GP.
• Support attendance at follow-up and rehabilitation appointments.
• Remember that family members can also feel shocked and frightened, and need information and support. The Stroke Association offers information, support groups and a helpline.

Developing your knowledge

Emergency recognition is a core professional skill. Record your learning in a CPD log, practise scenarios with colleagues and explore our CPD resources for care staff to keep your knowledge up to date.

Frequently asked questions

Is a subarachnoid haemorrhage the same as a stroke?

The NHS describes it as a rare type of stroke that causes bleeding on the brain.

What is a thunderclap headache?

The NHS uses the term for a sudden, extremely painful headache that does not go away. It needs a 999 call.

Can people recover fully?

The NHS says most people improve with treatment and some recover fully, though SAH can cause lasting disability.

This article draws on the NHS subarachnoid haemorrhage page (last reviewed September 2025).