Nursing care
Stroke symptoms on waking: setting last known well and acting fast
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated October 2026
Short answer
Activate the stroke response, check airway, breathing and circulation, check blood glucose, and establish last known well: the last time the client was seen or known to be normal, not the time symptoms were found. Keep the client nil by mouth until a swallow screen. Imaging decides whether treatment is still possible, so the nurse never assumes ineligibility.
First actions: stroke alert, ABCs and glucose
A client who wakes with facial droop, arm drift or slurred speech is treated as an acute stroke. The nurse checks airway, breathing and circulation, activates the stroke team or emergency response according to the facility, and performs a rapid neurological assessment. A bedside glucose check is essential because low blood glucose can mimic a stroke and must be excluded before thrombolysis.
Keep the client nil by mouth, including oral medicines and water, until a swallow screen is done, because dysphagia is common after stroke and aspiration is a real risk. Establish intravenous access as the protocol directs and prepare the client for urgent brain imaging. These steps run in parallel with gathering the timeline.
How last known well is set
Treatment windows start at the moment the patient was last observed to be well. When symptoms are found on waking, the onset is unknown, so last known well is usually the time the client went to sleep or was last seen normal. If the client woke during the night and was normal then, that later time becomes last known well.
The time the client was found, or the time they woke with symptoms, is not the onset. Gather the timeline from the client if possible, family, roommates and staff records, such as a night-time vital-sign check or toileting entry in which normal behaviour was noted. Record the source of the time as well as the time itself.
Why the time matters for treatment
Alteplase is labelled for use within 3 hours of symptom onset, and some clients are treated up to 4.5 hours with added exclusions. A long gap since last known well may seem to rule treatment out, but imaging can change that. MRI showing a diffusion-weighted and FLAIR mismatch suggests recent ischaemia and may extend eligibility in wake-up stroke.
Mechanical thrombectomy can be considered up to 24 hours after onset when imaging shows salvageable brain tissue. That is why the nurse reports last known well accurately and quickly rather than deciding the client is outside every window. Eligibility is a team decision based on the timeline, examination and imaging, made under local stroke protocol.
Assessments to report while the team decides
While imaging is arranged, the nurse gathers information the stroke team needs to judge eligibility: current medicines, especially anticoagulants, recent surgery or bleeding, known previous strokes, baseline function and weight if the protocol uses it. Record a neurological assessment with a recognised scale used by the unit so later checks can be compared accurately.
Blood pressure is checked and reported, because thrombolysis requires it to be below set limits before treatment. Treat blood pressure only as the provider orders, and report readings promptly so the team can act on them within the protocol. Keep family nearby if possible, as they may confirm the timeline and the client's usual abilities, which helps the team weigh benefits and risks.
A hypothetical inpatient scenario
Imagine a hypothetical hospitalised client found at 0600 with right-sided weakness and slurred speech. An assistant documented helping him to the bathroom at 0200, when he walked and talked normally. The choices are recording 0600 as onset, recording 0200 as last known well, giving his morning aspirin with water, or waiting for the provider's morning round.
Recording 0200 as last known well and activating the stroke response is correct, because onset is anchored to the last confirmed normal time. Using 0600 overstates eligibility and could lead to unsafe treatment. Oral medicine before a swallow screen risks aspiration, and aspirin before imaging is not appropriate when bleeding has not been excluded. Waiting loses brain tissue.
Sources and further reading
MSD Manual Professional: Ischemic stroke. 3 and 4.5 hour thrombolysis windows, thrombectomy up to 24 hours with imaging selection, and blood glucose criteria before thrombolysis.
DailyMed: Activase (alteplase) prescribing information. Labelled stroke use within 3 hours of symptom onset and exclusion of intracranial haemorrhage first.
CDC: Signs and symptoms of stroke. BE FAST recognition and the importance of noting when symptoms began.
Acute reperfusion therapies for acute ischemic stroke patients with unknown time of symptom onset or in extended time windows: an individualized approach. Wake-up stroke timed from last seen well, and DWI-FLAIR mismatch on MRI to select patients for thrombolysis.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our neurological practice questions are the closest set to what this page covers.
Common questions
If a client wakes with stroke symptoms, when is last known well?
The last time the client was seen or known to be normal, often bedtime or a documented night-time check. It is not the time the symptoms were discovered.
Does an unknown onset time mean no treatment is possible?
Not necessarily. Advanced imaging may show recent ischaemia or salvageable tissue, which can allow thrombolysis or thrombectomy. The stroke team decides.
Why check blood glucose in suspected stroke?
Low blood glucose can mimic stroke symptoms, and a glucose check is required before thrombolysis is given.