5. Hypoglycemia and hyperglycemia: Hyperglycemia is when there is too much sugar in the blood and a blood sugar level of >15 would indicate a dangerous level. Hypoglycemia is when there is too little sugar in the blood and a blood sugar level of <4 is considered dangerous. The target range is 4-8.The above reading of 2.7 is an example of hypoglycemia, it is a dangerous level and first aid would need to be carried out in a situation like this.