Learn How Stroke Develops, How to Recognize the Warning Signs, and What First Responders Should Do
Imagine this.
You are sitting in a Bangkok restaurant when a man at the next table suddenly stops speaking. His right hand slips off the table. When he tries to answer a question, his words are confused and difficult to understand.
His wife looks at him.
“Are you okay? What’s wrong?”
He attempts to smile, but one side of his mouth barely moves.
At first, someone suggests that he may be tired. Another person thinks he might have low blood sugar. A third suggests giving him some water.
But you recognize something more serious.
You ask him to raise both arms. His right arm drifts downward. His speech remains abnormal. These changes appeared suddenly.
You tell someone to call Thailand’s emergency medical services on 1669.
You note the time the symptoms began, stay with the patient, monitor his breathing, and prepare to hand over essential information to the ambulance crew.
You do not wait to see whether he improves.
You do not give him food, water, aspirin, or other medication.
You understand that every minute matters.
This is the reality of stroke recognition. The emergency may begin with symptoms that appear deceptively simple: a strange smile, an unsteady step, a sudden headache, or difficulty finding the right words.
Yet behind those symptoms, a critical process may be taking place inside the brain.
A blood vessel may be blocked. A weakened vessel may have ruptured. Brain tissue may already be losing its supply of oxygen and glucose.
And while the patient may still be conscious and able to speak, irreversible neurological injury can be developing.
The central principle is:
A suspected stroke is a medical emergency. Recognize the signs, activate emergency medical services immediately, and minimize delays to specialist stroke treatment.
Understanding the underlying physiology helps explain why early recognition, appropriate first aid, and rapid hospital transport can make a profound difference to survival and long-term recovery.
1. What Is a Stroke?
A stroke is an acute neurological emergency caused by a problem with blood circulation in the brain or, in some cases, bleeding around the brain.
The brain depends on a continuous supply of oxygen and glucose to maintain its electrical activity, communication between neurons, and control of essential functions such as movement, speech, consciousness, and breathing.
Unlike some tissues, the brain has very limited energy reserves. When blood flow is interrupted, the affected tissue can rapidly become dysfunctional.
There are two principal categories of stroke.
Ischemic stroke: A blocked blood vessel
An ischemic stroke occurs when an artery supplying the brain becomes obstructed, reducing or stopping blood flow to the affected region.
Ischemic strokes account for approximately 80–85% of strokes in many populations, although the exact proportion varies by population and classification method.
Common mechanisms include:
- Thrombosis: A blood clot forms within an artery, often on top of atherosclerotic plaque.
- Embolism: Material, frequently a blood clot originating elsewhere, travels through the circulation and blocks a cerebral artery.
- Small-vessel occlusion: Damage to small penetrating arteries, often associated with long-standing hypertension or diabetes, blocks blood flow to a small area of deep brain tissue.
A particularly important source of emboli is atrial fibrillation, an abnormal heart rhythm that can allow blood to stagnate in the atria and form clots. A clot can then travel to the brain and obstruct an artery.
The result is reduced oxygen delivery to neurons downstream from the blockage.
Hemorrhagic stroke: A ruptured blood vessel
A hemorrhagic stroke occurs when a blood vessel ruptures and blood escapes into or around the brain.
The two major categories are:
- Intracerebral hemorrhage: Bleeding directly into brain tissue.
- Subarachnoid hemorrhage: Bleeding into the space surrounding the brain, often associated with a ruptured aneurysm.
Hemorrhage can injure brain tissue directly. The accumulating blood may also increase pressure inside the skull, compress nearby structures, disrupt circulation, and contribute to secondary injury.
High blood pressure is an important risk factor for intracerebral hemorrhage, while ruptured cerebral aneurysms are a major cause of spontaneous subarachnoid hemorrhage.
The distinction between ischemic and hemorrhagic stroke is critical because their medical treatments differ.
You cannot reliably determine whether a stroke is caused by a clot or bleeding from symptoms alone. Brain imaging is required to establish the diagnosis and guide treatment.
This is why first aiders should recognize the emergency rather than attempt to diagnose the stroke subtype.
2. What Happens Inside the Brain During a Stroke?
To understand why rapid treatment matters, it is useful to examine the relationship between cerebral blood flow, oxygen delivery, and neuronal function.
The brain's demand for oxygen and glucose
Although the brain represents only a small proportion of total body mass, it consumes a substantial share of the body's oxygen and energy supply.
Neurons require energy to maintain electrical gradients across their cell membranes. These gradients allow nerve impulses to travel and enable communication between brain cells.
When an artery becomes blocked, the supply of oxygen and glucose decreases.
The affected cells can no longer produce sufficient energy through normal aerobic metabolism. ATP levels fall, membrane ion pumps begin to fail, and abnormal concentrations of sodium and calcium accumulate inside cells.
This triggers a cascade of damaging processes, including excessive release of glutamate, excitotoxicity, oxidative stress, and activation of pathways that injure cellular structures.
If the interruption in blood flow persists, neurons may become irreversibly damaged.
The ischemic core and the penumbra
An ischemic stroke does not necessarily destroy every affected cell immediately.
Clinicians often describe two important regions.
The ischemic core
This is the area where blood flow has fallen so severely that tissue injury is usually irreversible by the time treatment is established.
The ischemic penumbra
This is surrounding tissue that is receiving inadequate blood flow but may remain viable for a limited period.
The penumbra is one of the most important concepts in acute stroke management.
The objective of emergency treatment is to restore blood flow when appropriate and preserve threatened tissue before irreversible injury progresses.
However, the speed of deterioration varies according to the location of the blockage, the amount of residual blood flow, collateral circulation, and other patient-specific factors.
There is no universal countdown that determines exactly when every affected cell will die.
The clinical principle remains clear:
Time lost before effective treatment can mean brain tissue lost.
Why symptoms depend on the location of the injury
The brain is organized into specialized regions connected by complex networks.
When a stroke affects the left cerebral hemisphere, a patient may develop weakness on the right side of the body or difficulty producing or understanding language.
A stroke affecting the right hemisphere may produce left-sided weakness, spatial awareness problems, or neglect of one side of the environment.
Involvement of the brainstem or cerebellum may cause severe dizziness, impaired coordination, double vision, difficulty swallowing, or problems with balance.
These patterns are useful for clinicians, but symptoms do not always follow a textbook presentation.
A patient may have a stroke without obvious facial drooping. Another may remain able to walk but suddenly develop double vision and severe imbalance.
First aiders should therefore recognize sudden neurological changes, not rely exclusively on one symptom.
3. Why Some Strokes Are Caused by Clots and Others by Bleeding
Although ischemic and hemorrhagic strokes can produce similar symptoms, their underlying mechanisms differ.
Ischemic stroke: Occlusion and impaired perfusion
Atherosclerosis develops when cholesterol-containing material, inflammatory cells, and other substances accumulate in arterial walls.
Over time, plaques can narrow arteries. If a plaque ruptures, a blood clot may form and obstruct blood flow.
Alternatively, a clot formed elsewhere, particularly in the heart, can travel to a cerebral artery.
The resulting process can be summarized as:
Arterial obstruction → reduced cerebral blood flow → impaired oxygen and glucose delivery → cellular energy failure → neurological dysfunction and possible tissue death.
Treatment may involve intravenous thrombolytic medication to dissolve a clot in eligible patients, or mechanical thrombectomy to remove an accessible clot using specialized endovascular techniques.
Not every patient is eligible for every treatment. Decisions depend on the clinical presentation, imaging findings, time course, contraindications, and specialist assessment.
Hemorrhagic stroke: Vessel rupture and intracranial injury
In hemorrhagic stroke, blood escapes from a damaged vessel.
The injury may result from small-vessel disease associated with hypertension, a ruptured aneurysm, vascular abnormalities, or other causes.
The consequences include direct tissue damage, local inflammation, possible expansion of the hematoma, and increased intracranial pressure.
Treatment may involve carefully controlled blood pressure management, reversal of anticoagulant effects when indicated, specialist neurosurgical or neurocritical care, and treatment of the underlying vascular cause.
A patient with hemorrhagic stroke may require very different treatment from someone with an ischemic stroke.
This distinction explains an essential first-aid rule:
Never give aspirin to someone with a suspected stroke unless a qualified clinician specifically directs it after appropriate assessment.
Aspirin affects platelet function and may worsen bleeding in a hemorrhagic stroke. The stroke subtype cannot be safely established by a bystander.
4. The Most Important Warning Signs: BE-FAST
Recognizing stroke early is one of the most valuable actions a first aider can take.
The BE-FAST method is a practical recognition tool covering six warning signs.
B — Balance
Ask whether the person has suddenly developed:
- Loss of balance.
- Difficulty walking.
- New coordination problems.
- Unexplained unsteadiness.
Sudden imbalance can reflect dysfunction in the cerebellum or brainstem, although other medical conditions can produce similar symptoms.
E — Eyes
Look for sudden visual changes, including:
- Loss of vision in one or both eyes.
- Double vision.
- Sudden blurred vision.
- A new visual field defect.
A patient may describe a curtain over one eye or suddenly become unable to see objects on one side.
Do not dismiss a sudden visual disturbance simply because the patient's face and speech appear normal.
F — Face
Ask the person to smile or show their teeth.
Look for asymmetry, such as one side of the mouth drooping.
Facial weakness may occur because a stroke disrupts the motor pathways controlling facial muscles.
A normal smile does not exclude stroke.
A — Arms
Ask the person to raise both arms and hold them up if they are able.
Observe whether one arm is weak, drifts downward, or cannot be lifted normally.
New weakness or numbness affecting one side of the body is a significant warning sign.
Do not force a movement if the patient is injured or unable to cooperate safely.
S — Speech
Ask the person to repeat a simple sentence.
Listen for:
- Slurred speech.
- Incorrect or unusual words.
- Difficulty finding words.
- Inability to speak.
- Difficulty understanding what is being said.
Speech disturbances may reflect weakness of the muscles used for speaking or disruption of the brain's language networks.
A person may appear confused because they cannot understand language, rather than because they are unwilling to cooperate.
T — Time
Time means activating emergency medical services immediately.
In Thailand, call 1669 for emergency medical assistance.
Tell the dispatcher that you suspect a stroke and describe the observed symptoms.
Record:
- The exact time symptoms were first noticed.
- The last time the person was known to be at their usual neurological baseline, if known.
- Whether the symptoms are improving, persisting, or worsening.
The distinction between symptom recognition and last known well is particularly important when the patient wakes up with symptoms or nobody witnessed the onset.
Do not wait for all BE-FAST signs to appear. One sudden neurological deficit may be enough to justify emergency activation.
BE-FAST is a screening aid, not a diagnostic test. A person can have a stroke even when the screening findings are incomplete or atypical.
5. Other Symptoms That May Indicate a Stroke
Stroke can produce a broad range of neurological symptoms.
Additional warning signs include:
- Sudden weakness or numbness affecting the face, arm, or leg.
- Sudden confusion or difficulty understanding others.
- Sudden difficulty swallowing.
- New loss of coordination.
- Sudden severe headache, particularly when accompanied by vomiting, neck stiffness, or reduced consciousness.
- New double vision or abnormal eye movements.
- Sudden loss of consciousness.
- New difficulty standing or walking.
A sudden, exceptionally severe headache may be associated with subarachnoid hemorrhage, but headache alone does not establish the diagnosis.
Likewise, dizziness is common and often has causes unrelated to stroke. However, sudden severe imbalance, especially when accompanied by double vision, weakness, speech changes, or coordination problems, requires urgent assessment.
Stroke can resemble other medical emergencies
Several conditions can produce symptoms that resemble stroke, including:
- Hypoglycemia.
- Seizures and the period following a seizure.
- Migraine with neurological symptoms.
- Certain metabolic disturbances.
- Other neurological disorders.
Low blood glucose is particularly important because it can produce confusion, weakness, abnormal behavior, and other neurological findings.
Healthcare professionals may measure blood glucose during the initial assessment because identifying hypoglycemia can change immediate management.
However, bystanders should not delay emergency activation while attempting to establish the cause.
The correct approach is to treat sudden neurological symptoms as a medical emergency until qualified professionals have assessed the patient.
6. Why Time Matters: The Stroke Treatment Window
Stroke treatment is time-sensitive because some therapies are most effective when delivered early.
The exact treatment window depends on the type of stroke, the treatment being considered, and the patient's clinical and imaging findings.
Intravenous thrombolysis
Eligible patients with acute ischemic stroke may receive intravenous thrombolytic treatment, such as alteplase or tenecteplase, depending on the applicable guideline and hospital protocol.
For appropriately selected patients, treatment is generally considered within 4.5 hours of symptom onset or last known well.
Some patients with an unknown onset time or later presentation may qualify under specialized imaging-based selection criteria.
Thrombolytic treatment is not appropriate for every stroke patient. In particular, intracranial bleeding must be excluded and relevant contraindications assessed.
Mechanical thrombectomy
Some ischemic strokes are caused by large-vessel occlusions.
Mechanical thrombectomy uses an endovascular device to remove a clot from an affected artery.
Eligible patients may benefit from thrombectomy within the early hours after onset. Selected patients can also benefit as late as 24 hours after last known well when clinical and imaging criteria support treatment.
This does not mean that waiting is safe.
Earlier assessment allows clinicians to identify eligible patients and begin appropriate treatment as quickly as possible.
What should first aiders understand?
You do not need to determine which treatment the patient might receive.
Your priorities are to:
- Recognize the symptoms.
- Activate emergency medical services.
- Establish the time of onset or last known well.
- Monitor the patient's condition.
- Avoid interventions that could cause harm.
- Support rapid transfer to an appropriate hospital.
The treatment window is a clinical decision-making window, not permission to delay calling an ambulance.
7. The First-Aid Response to Suspected Stroke
First aid cannot reverse a blocked artery or repair a ruptured cerebral vessel. Its purpose is to protect the patient, recognize deterioration, and reduce avoidable delays until professional treatment begins.
Step 1: Ensure scene safety
Before approaching, check for immediate hazards.
Consider traffic, moving machinery, electrical hazards, environmental dangers, or other threats.
Do not put yourself or others at unnecessary risk.
Step 2: Assess responsiveness
Approach the person, introduce yourself, and check whether they respond appropriately.
Ask simple questions and observe their ability to speak and follow instructions.
If the patient is unresponsive, assess breathing and follow the appropriate emergency response pathway.
Step 3: Activate EMS immediately
Call 1669 in Thailand, or direct a specific person to make the call.
Clearly state:
- The location and access details.
- That stroke is suspected.
- The patient's current symptoms.
- The time symptoms began or the last known well time, if known.
- Any deterioration, loss of consciousness, or breathing abnormality.
Put the call on speaker if appropriate so you can continue monitoring the patient while following dispatcher instructions.
Do not wait for symptoms to disappear.
Step 4: Note the time
Ask the patient or witnesses when the symptoms began.
If the onset time is uncertain, record the last time the person was known to be normal.
For example:
- Last known well: 13:10.
- Symptoms discovered: 14:00.
These are different pieces of information, and both may be important to the hospital team.
Do not guess or invent an onset time if nobody knows it.
Step 5: Position the patient safely
Help the patient remain in a comfortable, supported position.
If conscious and breathing normally, allow a position that supports breathing and minimizes the risk of falling. Avoid unnecessary movement.
If the patient is drowsy, has difficulty swallowing, or is vomiting, airway protection becomes a priority. Follow dispatcher instructions and use an appropriate position if safe.
If the person becomes unresponsive but continues to breathe normally, place them in the recovery position when appropriate, taking account of possible trauma and maintaining an open airway.
If normal breathing is absent or the person is only gasping, initiate CPR according to your training and dispatcher instructions.
Step 6: Do not give food, drink, or medication
A stroke can impair swallowing without obvious warning.
Giving water, food, or oral medication may cause choking or aspiration, allowing material to enter the lungs.
Do not give:
- Water or other drinks.
- Food or sweets.
- Aspirin.
- Blood pressure medication.
- Other oral medication.
Do not attempt to lower the patient's blood pressure yourself.
The appropriate management depends on the stroke subtype and clinical condition. Allow trained clinicians to assess and treat the patient.
Step 7: Monitor breathing and consciousness
Stay with the patient.
Observe whether they become more confused, drowsy, unresponsive, or unable to maintain their airway.
Watch for vomiting, seizures, or changes in breathing.
If their condition deteriorates, update the emergency dispatcher.
If they stop responding and are not breathing normally, begin CPR and use an AED if indicated and available, following your training and the dispatcher's instructions.
An AED does not treat the underlying stroke, but it may be necessary if the patient develops cardiac arrest.
Step 8: Prepare the handover
When the ambulance arrives, provide a concise report.
Include:
- The patient's age, if known.
- The symptoms observed.
- The time symptoms began or the last known well time.
- Changes in symptoms.
- Any loss of consciousness or seizure.
- Relevant medical history known to you.
- Any medication information provided by the patient or family.
- Actions taken and the patient's response.
Accurate information can help emergency clinicians prioritize assessment and treatment.
8. What First Aiders Must Not Do
Some well-intentioned actions can create additional risks or delay treatment.
Do not wait for symptoms to improve
Symptoms that resolve may indicate a transient ischemic attack, or TIA, rather than a completed stroke.
However, a TIA is not harmless. It is an important warning of possible future stroke and requires urgent medical assessment.
Never cancel emergency care simply because the patient appears better.
Do not give aspirin
Aspirin may be used in selected patients after clinicians have assessed the situation and excluded intracranial hemorrhage as appropriate.
It is not a safe default first-aid treatment for an undiagnosed stroke.
Do not give food or drink
Swallowing impairment may be subtle. Nothing should be given by mouth until the patient has been appropriately assessed.
Do not attempt to lower blood pressure
High blood pressure is common during acute stroke. However, the appropriate blood pressure strategy depends on the stroke subtype, planned treatment, and clinical circumstances.
An untrained responder should not administer medication or attempt to manipulate the patient's blood pressure.
Do not move the patient unnecessarily
Avoid making the person walk, stand, or travel in a private vehicle when EMS transport is available.
Emergency services can assess the patient, monitor deterioration, and coordinate appropriate hospital care.
Do not assume the patient is drunk or merely tired
Slurred speech, confusion, and poor coordination can be mistaken for alcohol intoxication.
When symptoms appear suddenly, stroke must remain a serious consideration.
9. Transient Ischemic Attack: When Symptoms Disappear
A transient ischemic attack occurs when neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia resolves without evidence of acute infarction under the modern tissue-based definition.
Patients may experience temporary weakness, speech difficulties, visual loss, or other stroke-like symptoms.
The symptoms can disappear before medical help arrives.
This creates a dangerous misconception: if the patient looks normal again, the emergency has passed.
It has not necessarily passed.
A TIA may indicate significant underlying vascular disease or a source of emboli that could cause a subsequent stroke.
Clinical assessment is required to distinguish TIA from completed ischemic stroke and other conditions that mimic them.
The response is therefore the same at the first-aid level:
Activate emergency medical services and obtain urgent medical assessment, even if the symptoms have completely resolved.
10. Risk Factors: Why Stroke Happens
Some stroke risk factors cannot be changed, but many can be managed.
Understanding them helps explain why prevention and early medical care are so important.
High blood pressure
Hypertension is a major modifiable risk factor for both ischemic and hemorrhagic stroke.
Over time, elevated pressure damages arterial walls, contributes to atherosclerosis and small-vessel disease, and increases the risk of vessel rupture.
Regular blood pressure assessment and appropriate treatment are central to prevention.
Atrial fibrillation
Atrial fibrillation can promote clot formation within the heart.
A clot may travel through the circulation and obstruct a cerebral artery.
Some patients benefit from anticoagulant medication to reduce this risk, but treatment decisions must be made by qualified clinicians.
Diabetes
Diabetes contributes to vascular damage and increases the risk of stroke through several mechanisms, including its association with hypertension and atherosclerotic disease.
Appropriate glucose management and cardiovascular risk reduction are important preventive measures.
High cholesterol and atherosclerosis
Elevated levels of atherogenic lipoproteins contribute to plaque formation within arteries.
Plaques may narrow vessels or rupture, triggering clot formation.
Dietary measures, exercise, and medication when indicated can reduce cardiovascular risk.
Smoking
Smoking damages blood vessels and increases the risk of atherosclerosis and thrombosis.
Stopping smoking is an important step toward reducing stroke risk.
Other risk factors
Additional factors include:
- Physical inactivity.
- Obesity.
- Excessive alcohol consumption.
- Certain heart and vascular diseases.
- Older age.
- Family history and genetic factors.
- Previous stroke or TIA.
Risk is influenced by the combination of these factors, not by any single characteristic alone.
People with known risk factors should work with qualified healthcare professionals to assess and manage their individual cardiovascular risk.
11. How Paramedics and Stroke Teams Manage Suspected Stroke
Prehospital care and hospital treatment are coordinated components of the stroke pathway.
The objective is to identify a possible stroke rapidly, support vital functions, and minimize the time required to establish the diagnosis and initiate appropriate treatment.
Initial assessment
Emergency clinicians assess the patient's airway, breathing, circulation, level of consciousness, and neurological findings.
They obtain information about symptom onset, last known well, medical history, and medication use.
Blood glucose is often checked early because hypoglycemia can imitate stroke and requires different treatment.
Other measurements and investigations depend on the patient's condition and the local EMS protocol.
Stroke screening and hospital notification
Paramedics use appropriate neurological assessment tools and follow local stroke pathways.
When stroke is suspected, advance notification can help the receiving hospital prepare the stroke team and imaging facilities.
The choice of destination depends on regional protocols, the patient's condition, transport time, and access to appropriate stroke services.
Brain imaging
Non-contrast CT is commonly used to identify intracranial hemorrhage and assess the brain during initial evaluation.
CT angiography may be used to identify large-vessel occlusion and evaluate cerebral vessels.
MRI and advanced imaging techniques can be valuable in selected circumstances, including some patients with an uncertain onset time.
Imaging helps clinicians determine whether reperfusion treatment is appropriate and identify alternative causes of neurological symptoms.
Reperfusion treatment
For eligible ischemic stroke patients, thrombolytic treatment may dissolve an obstructing clot.
For selected large-vessel occlusions, mechanical thrombectomy may restore blood flow by physically removing the clot.
These treatments can improve outcomes, but they are not suitable for every patient and must be delivered according to evidence-based protocols.
Management of hemorrhagic stroke
When bleeding is identified, treatment focuses on limiting further injury.
Depending on the cause and severity, this may include blood pressure management, reversal of anticoagulation, neurocritical care, and neurosurgical or endovascular intervention.
The distinction between hemorrhagic and ischemic stroke demonstrates why definitive diagnosis is essential.
12. Why Prehospital Recognition Can Change the Outcome
The emergency response begins before the patient reaches hospital.
A bystander who recognizes sudden facial asymmetry, arm weakness, or speech disturbance may be the first person capable of identifying the emergency.
A timely call allows EMS to begin assessment and arrange appropriate transport.
A witness who accurately records the onset or last known well time can provide information that affects treatment eligibility.
A first aider who avoids giving oral medication, monitors the patient's breathing, and recognizes deterioration can prevent additional complications.
None of these actions requires a bystander to diagnose the precise type of stroke.
They require recognition, timely communication, and appropriate first aid.
The first aider's role is not to repair the damaged artery. It is to recognize the emergency, protect the patient, and help ensure that definitive treatment begins without avoidable delay.
13. The Four Questions Every First Aider Should Ask
When confronted with sudden neurological symptoms, remember four questions.
1. Did the symptoms begin suddenly?
Sudden weakness, speech difficulty, visual disturbance, or loss of coordination should raise suspicion of stroke.
2. Is there any new neurological deficit?
Look for facial asymmetry, arm weakness, abnormal speech, sudden imbalance, or visual changes.
Do not require all signs to be present.
3. Has emergency medical assistance been activated?
Call 1669 in Thailand and clearly report the suspected stroke.
Do not delay because the patient is young, has no known medical history, or appears to be improving.
4. What information can help the stroke team?
Establish the symptom onset or last known well time, observe changes, identify relevant medical history when possible, and provide an accurate handover.
Then continue monitoring the patient's breathing and level of consciousness.
These four questions help turn recognition into a practical emergency response.
14. Final Summary
A stroke is a time-critical neurological emergency caused primarily by either interruption of cerebral blood flow or bleeding into or around the brain.
The two principal categories are:
Ischemic stroke
A blood vessel is obstructed, reducing oxygen and glucose delivery to brain tissue.
Treatment may involve thrombolysis or mechanical thrombectomy in appropriately selected patients.
Hemorrhagic stroke
A blood vessel ruptures, causing bleeding and potentially increasing pressure inside the skull.
Treatment may involve blood pressure management, reversal of anticoagulation when indicated, and specialist neurological or neurosurgical care.
The major warning signs can be remembered using BE-FAST:
- B — Balance: Sudden loss of balance or coordination.
- E — Eyes: Sudden visual disturbance.
- F — Face: Facial drooping or asymmetry.
- A — Arms: New weakness or numbness.
- S — Speech: Difficulty speaking or understanding.
- T — Time: Call emergency medical services immediately.
The priorities for first aid are:
- Ensure scene safety.
- Assess responsiveness and breathing.
- Call 1669 in Thailand.
- Record symptom onset or last known well.
- Keep the patient safe and monitor their condition.
- Give nothing by mouth and do not administer aspirin.
- Start CPR if the patient becomes unresponsive and is not breathing normally.
- Provide an accurate handover to EMS.
A transient improvement does not eliminate the need for urgent assessment.
Likewise, the absence of one or more classic BE-FAST signs does not rule out stroke.
The objective is not to diagnose the stroke subtype at the scene. It is to recognize the possibility of a stroke and minimize delays to definitive care.
Recognize the signs. Call for help. Record the time. Protect the patient. Every minute matters.
Scientific References and Further Reading
This article is informed by peer-reviewed medical literature and evidence-based clinical guidelines covering stroke pathophysiology, risk factors, recognition, first aid, and acute management.
1. Powers, W. J., Rabinstein, A. A., Ackerson, T., et al. (2019). Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines. Stroke, 50, e344–e418.
https://doi.org/10.1161/STR.0000000000000211
Relevance: Acute ischemic stroke assessment, thrombolytic treatment, emergency pathways, and time-sensitive reperfusion therapy.
2. Greenberg, S. M., Ziai, W. C., Cordonnier, C., et al. (2022). 2022 Guideline for the Management of Patients With Spontaneous Intracerebral Hemorrhage. Stroke, 53, e282–e361.
https://doi.org/10.1161/STR.0000000000000407
Relevance: Intracerebral hemorrhage, acute blood pressure management, anticoagulant reversal, and specialist treatment.
3. Hoh, B. L., Ko, N. U., Amin-Hanjani, S., et al. (2023). 2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage. Stroke, 54, e314–e370.
https://doi.org/10.1161/STR.0000000000000436
Relevance: Recognition and management of aneurysmal subarachnoid hemorrhage.
4. Kleindorfer, D. O., Towfighi, A., Chaturvedi, S., et al. (2021). 2021 Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack. Stroke, 52, e364–e467.
https://doi.org/10.1161/STR.0000000000000375
Relevance: Secondary prevention, vascular risk factors, and management following ischemic stroke or TIA.
5. Easton, J. D., Saver, J. L., Albers, G. W., et al. (2009). Definition and Evaluation of Transient Ischemic Attack. Stroke, 40, 2276–2293.
https://doi.org/10.1161/STROKEAHA.108.192218
Relevance: The tissue-based definition of TIA and the importance of urgent assessment after transient neurological symptoms.
6. Hewett Brumberg, E. K., Douma, M. J., Alibertis, K., et al. (2024). 2024 American Heart Association and American Red Cross Guidelines for First Aid. Circulation, 150, e519–e579.
https://doi.org/10.1161/CIR.0000000000001281
Relevance: Evidence-based first aid principles, emergency activation, and appropriate care while awaiting professional assistance.
7. American Heart Association/American Stroke Association. Stroke resources and clinical guidance.
https://www.stroke.org/
Relevance: Stroke recognition, prevention, emergency response, and patient education.
Medical Disclaimer
This article is intended for educational purposes and does not replace professional medical training, clinical judgment, local emergency medical protocols, or advice from qualified healthcare professionals.
Suspected stroke is a medical emergency. Activate emergency medical services immediately and provide care within your level of training while awaiting professional assistance.
Don't Wait for a Stroke to Happen. Be Ready.
Stroke can affect people at home, at work, in schools, in hotels, during travel, or in public places. It may occur in a person with known cardiovascular risk factors or in someone whose medical history is unknown.
Recognizing the warning signs is only the first step. Knowing how to activate emergency services, protect the patient, monitor deterioration, and communicate effectively with responders requires practical preparation.
At Bangkok First Aid, our First Aid, CPR and AED training courses help individuals and organizations develop practical emergency response skills, including:
- Recognizing sudden neurological changes and suspected stroke.
- Understanding BE-FAST and other warning signs of medical emergencies.
- Activating emergency medical services and communicating essential information.
- Monitoring responsiveness and breathing.
- Providing appropriate first aid while awaiting an ambulance.
- Recognizing when CPR and an AED may be required.
- Practising emergency response through realistic scenarios.
Whether you are a parent, teacher, workplace first aider, healthcare professional, or member of an emergency response team, learning how to recognize a stroke can help you act decisively when seconds count.
Prepare before an emergency happens. Contact Bangkok First Aid and build the confidence to recognize a medical emergency and respond appropriately.