Why does hypoglycaemia cause slurred speech?

Speaking clearly requires the brain to plan words and precisely control muscles of the mouth and tongue. When glucose is low, these tasks can be affected, making speech sound thick, slow or difficult to understand. Slurred Speech is a common presentation of Hypoglycaemia and may occur with confusion, poor coordination, blurred vision or unusual behaviour. Slurred speech can also be a sign of stroke, a seizure, alcohol or medication effects, migraine, or another neurological problem. It should never be dismissed based on the sound of the speech alone.

Stop what you are doing and ask someone to stay with you. If you can use a meter or sensor, check glucose. If you are fully awake and swallowing normally, follow your individual low-glucose treatment plan. Do not drive or use equipment while speech or thinking is affected. If another person has slurred speech, check whether they can smile evenly, raise both arms and understand simple questions, but do not delay emergency help while trying to assess them. Note the onset time and any glucose reading for the clinical team.

Call emergency services urgently for sudden slurred speech, especially with facial drooping, arm weakness, severe headache, new loss of balance, confusion or loss of consciousness. Seek emergency help if swallowing is unsafe, the person has a seizure, or symptoms persist after treatment directed by their low-glucose plan. Even when speech improves, a new episode deserves prompt medical review because other neurological causes may need to be ruled out.

Ask how your diabetes medicines, meal pattern and activity may influence low-glucose episodes. Discuss what family, colleagues or carers should do if your words become unclear, and whether you should carry a written emergency plan or rescue medicine.