When to contact a doctor
Call 108 immediately. Note when the person was last known to be well, including before sleep if they woke with symptoms. Do not wait for symptoms to improve or for a routine appointment. Avoid giving food, drink or aspirin unless the emergency team instructs you. Treatment may still be possible when the exact onset time is uncertain.
What you may notice
A stroke can cause sudden facial droop, arm or leg weakness, altered speech, loss of vision or new difficulty with balance. Symptoms may affect one side. Even symptoms that disappear can be a warning of a temporary interruption of brain blood flow.
Brain and an enlarged artery segment
What could cause it?
A blocked artery and bleeding in the brain can both cause stroke symptoms. Low blood sugar, seizures and migraine can sometimes mimic them. Symptoms alone cannot safely distinguish these causes; emergency examination and brain imaging are needed. Do not decide at home that it is only migraine or tiredness.
How interventional radiology may help
For eligible patients with a large blocked brain artery, neurointervention can remove the clot through a catheter. Clot-dissolving medicine may also be appropriate. Imaging, time, the affected tissue and the patient's condition determine treatment. Brain haemorrhage follows a different pathway; surgery, intensive care or treatment of an abnormal vessel may be needed.
Further reading: detailed assessment and treatment options
Patient information sources
References are in English.
Educational information, not a diagnosis. The causes listed are examples, not a complete list. Tests and treatment depend on your individual assessment.