How common is fainting in hypoglycaemia?

The brain needs glucose to work. When blood glucose falls, early symptoms may include sweating, trembling, hunger, a fast heartbeat, anxiety, dizziness, blurred vision, irritability, or difficulty concentrating. If the level falls further, a person may become confused, have a seizure, or lose consciousness. This can occur in people using insulin or other glucose-lowering medicines, and other causes are possible.

A reading from a glucose meter can be useful if it is available and does not delay help. A blackout can also result from dehydration, a heart rhythm problem, or a seizure, so repeated or unexplained episodes need clinical review.

If the person is awake and can swallow safely, use their usual fast-acting glucose treatment and recheck or reassess as advised in their care plan. If they are unconscious, having a seizure, or unable to swallow, do not put food, drink, or tablets in their mouth. Place them on their side, use prescribed rescue treatment if trained, and call emergency services.

Call emergency services if consciousness does not return promptly, symptoms recur, a seizure or injury occurs, the person cannot swallow, or there is no clear improvement after their prescribed rescue plan. Seek prompt medical advice after any blackout, especially if medicines, meals, alcohol, exercise, or illness may have contributed.

Ask which symptoms and readings should trigger treatment, how to adjust food or medicines around exercise, whether you should carry rescue glucose, and when an unexplained blackout needs further testing.