Overview
A stroke occurs when the blood supply to part of the brain is cut off, killing brain cells within minutes. There are two main types: ischaemic stroke (caused by a blood clot, 85% of cases) and haemorrhagic stroke (caused by a burst blood vessel). Stroke is a medical emergency — remember the FAST test. Every minute of delay results in approximately 1.9 million brain cells dying. Immediate treatment significantly improves outcomes.
Causes and risk factors
The following factors are associated with the development of Stroke:
- Blood clot blocking a brain artery (ischaemic stroke)
- Ruptured blood vessel in or around the brain (haemorrhagic)
- Atrial fibrillation — causes blood clots
- High blood pressure — most important modifiable risk factor
- High cholesterol
- Smoking
- Diabetes
- Heart disease
- Excessive alcohol
- Obesity
- Family history
Signs and symptoms
Common signs and symptoms of Stroke include:
- Face drooping on one side — ask them to smile
- Arm weakness — cannot raise both arms
- Speech difficulty — slurred or unable to speak
- Time to call 999/112 IMMEDIATELY
- Sudden severe headache with no known cause
- Sudden vision problems in one or both eyes
- Sudden confusion or difficulty understanding
- Sudden severe dizziness or loss of balance
Diagnosis
Stroke is typically diagnosed through a combination of medical history, physical examination, and appropriate investigations such as blood tests, imaging, or specialist review, depending on the specific condition and presentation. Your doctor will consider all relevant symptoms and risk factors before making a diagnosis.
Treatment options
Treatment approaches for Stroke may include:
- Emergency call 999/112 immediately
- Thrombolysis (tPA clot-busting drug) within 4.5 hours for ischaemic stroke
- Thrombectomy — mechanical clot removal within 24 hours
- Blood pressure control for haemorrhagic stroke
- Aspirin and anticoagulants to prevent further clots
- Rehabilitation: physiotherapy, speech therapy, occupational therapy
- Medications to prevent recurrence: antihypertensives, statins
Prevention
Control blood pressure, stop smoking, treat atrial fibrillation, maintain healthy diet and weight, exercise, limit alcohol, control diabetes.
Complications
If left untreated or poorly managed, Stroke can lead to complications including:
Permanent disability, paralysis, speech problems, cognitive impairment, depression, and death.
Sources and references: This article is written in accordance with NHS UK, WHO, and Mayo Clinic clinical guidelines. It is reviewed for accuracy by the SymptomSense content team. ICD-10 code: I63. Last reviewed June 2026.