Stroke weakness on the left side: what to know

Weakness on the left side can be a sign of stroke and needs emergency assessment, especially when it starts suddenly. Stroke symptoms may involve the face, arm or leg, speech, vision, balance or alertness. Do not drive yourself or wait to see whether the weakness settles.

A stroke affecting the right side of the brain can disrupt movement or sensation on the left side of the body. Some people also develop numbness, clumsiness, facial drooping, difficulty speaking, confusion or a severe new headache. The pattern and timing help clinicians distinguish stroke from other causes. Risk factors include hypertension, atrial fibrillation and type 2 diabetes; these do not make every episode a stroke, but they make prompt assessment especially important.

Note the time the person was last known to be well, call emergency services and keep them safe while help arrives. Do not give food, drink or medicines unless an emergency professional advises it, because swallowing may be affected. Take a list of medicines and known conditions to hospital if it is immediately available. Assessment may include a neurological examination and brain imaging.

Call emergency services immediately for sudden one-sided weakness, facial drooping, new speech trouble, loss of balance, vision change or unusual drowsiness, even if the symptoms improve. A short-lived episode can still require urgent evaluation. Do not use symptom improvement as a reason to delay.

Ask what part of the brain was affected, whether rehabilitation is recommended, how swallowing and movement will be checked, and which conditions or medicines need review to reduce future risk.