What should you know about dissection stroke?

The tear, called a dissection, may narrow the artery or allow a clot to form. A dissection can affect an artery in the neck or, less often, inside the head. Symptoms depend on which part of the brain loses blood flow. Sudden weakness or numbness on one side, trouble speaking, vision change, severe dizziness or loss of coordination can occur. A [Stroke](/conditions/stroke/) assessment may include brain and blood-vessel scans. Conditions such as [Hypertension](/conditions/hypertension/), [Atrial Fibrillation](/conditions/atrial-fibrillation/) and [Type 2 Diabetes](/conditions/type-2-diabetes/) can affect stroke risk, but they do not explain away sudden symptoms.

Treat sudden neurological symptoms as an emergency. Note when the person was last well, keep them safe, and call emergency services rather than driving them yourself. Do not give food, drink or medicines unless an emergency professional advises it. Hospital teams decide treatment after imaging; options may include medicines or procedures suited to the artery problem and the type of stroke. After discharge, attend the planned [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) and take prescribed [Blood Pressure Medication](/treatments/medical-management/blood-pressure-medication/) as directed. Do not stop treatment without medical advice.

Call emergency services immediately for facial drooping, one-sided weakness or [Numbness and Tingling](/symptoms/numbness-and-tingling/), new speech difficulty, sudden vision loss, collapse, or a severe unusual headache. Symptoms that improve can still signal a serious blood-flow problem and need urgent assessment. Seek emergency help for worsening headache, repeated vomiting, fainting or a new seizure.

Ask which artery was affected, what the scans showed, whether a clot or bleeding was present, which medicines are needed, how activity should change, and which symptoms should prompt an immediate return to hospital.