Types of Stroke: Understanding the Difference Between Ischemic and Hemorrhagic Stroke

The word "stroke" covers two very different medical events that look similar from the outside but require completely different treatments. Understanding this distinction is important for patients, families, and anyone who wants to know more about brain health.

Ischemic Stroke (Blood Clot): 80% of All Strokes

An ischemic stroke occurs when a blood vessel supplying the brain is blocked — either by a clot that formed in place (thrombosis) or a clot that travelled from elsewhere (embolism, most often from the heart or carotid artery). Without blood flow, brain cells begin to die within minutes.

Treatment:

• Intravenous thrombolysis (clot-busting injection): Must be given within 4.5 hours of symptom onset. Dissolves the clot and restores blood flow. Not suitable for all patients — contraindications include recent surgery, bleeding disorders, very high blood pressure.
• Mechanical thrombectomy: A catheter procedure to physically remove large clots from major arteries. Effective up to 24 hours from symptom onset in selected patients. Available in specialised stroke centres.
• Long-term prevention: Antiplatelet drugs (aspirin, clopidogrel) or anticoagulation (for atrial fibrillation), blood pressure control, statins.

Haemorrhagic Stroke (Brain Bleed): 20% of All Strokes, Higher Mortality

A haemorrhagic stroke occurs when a blood vessel in or around the brain ruptures, causing bleeding into the brain tissue (intracerebral haemorrhage) or into the space between the brain and the skull (subarachnoid haemorrhage).

Subarachnoid haemorrhage from a ruptured aneurysm presents with the classic "thunderclap headache" — sudden, severe, worst ever. Intracerebral haemorrhage often presents with similar symptoms to ischemic stroke but may cause worse headache and more rapid deterioration.

Treatment:

• Control blood pressure urgently
• Reverse any anticoagulation
• Neurosurgery for some cases — to clip or coil an aneurysm, or to evacuate a large blood clot
• Crucially: clot-busting drugs must NOT be given in haemorrhagic stroke — they would make the bleeding catastrophically worse. This is why a CT scan is always done before any stroke treatment.

TIA: The Warning Stroke

A TIA (Transient Ischaemic Attack) is a brief episode of stroke symptoms that resolves completely within 24 hours (usually within minutes). It is a serious warning: the risk of a major stroke in the following days is high. TIA must be treated as an emergency.

"When stroke symptoms occur, a CT scan within minutes determines whether it is a clot or a bleed — and therefore which treatment can be given. This is why the hospital needs to know immediately: time = brain."

Dr. Anand Karnam provides stroke diagnosis, acute management, and secondary prevention at Sri Anand Child and Neuro Center, Chanda Nagar. Call +91 90633 66983.