When is low blood glucose dangerous, and what should I do?
Low glucose can cause sweating, shaking or confusion, sometimes without warning. For many people with diabetes, a reading below 70 mg/dL requires action according to their treatment plan. Unconsciousness or inability to swallow is an emergency: do not give anything by mouth.
Details
If awake and able to swallow safely
The general adult approach is 15 grams of fast-acting carbohydrate, such as glucose tablets in the labelled amount, followed by a glucose check after 15 minutes. Repeat if still low. Children and people using automated insulin delivery may need different amounts under their own plan.
If the person cannot self-treat
Call emergency services for unconsciousness, seizure or unsafe swallowing. Give prescribed glucagon if available and you know how to use it. Do not force food or drink, give insulin to treat the low, or wait for an extremely low number.
After recovery
Follow the planned meal or snack advice. Recurrent lows or loss of warning symptoms need a review of medicines, meals and activity with the diabetes team. This answer does not replace an individual treatment plan.
Related reading: What is the difference between CGM and FreeStyle Libre sensors?.