How common is weakness on one side in stroke?

A stroke disrupts blood flow or causes bleeding in part of the brain. If the affected area controls movement, weakness may develop on the opposite side of the body. It can involve the face, arm, leg or several of these together, and may occur with numbness, speech difficulty, vision change, dizziness or loss of balance.

The exact pattern varies, and one-sided weakness can have causes other than stroke. However, a sudden change is treated as an emergency until assessed. Symptoms that improve still need urgent attention because a temporary episode can be a warning of further brain injury.

Record the time the person was last known to be well and call emergency services immediately. Keep them safe and supported; do not give food, drink or medicine unless emergency professionals advise it. Do not drive them yourself if an ambulance is available, because specialist teams can begin assessment during transport.

Note changes in the face, speech, strength, vision and alertness. Stay with the person and follow the dispatcher’s instructions while waiting.

Any sudden one-sided weakness needs emergency assessment, especially with facial drooping, unclear speech, confusion, severe headache, trouble walking, vision loss or difficulty swallowing. Call again if symptoms change while waiting. Never dismiss the episode because the person feels better; prompt assessment remains necessary.

Ask what type of stroke was suspected, which tests were performed, what medicines and rehabilitation may be needed, how to reduce future risk, and which warning signs should trigger another emergency call.