Hyperglycaemia indicates a high level of sugar in the blood, while hypoglycaemia, or “hypo”, indicates a level level of sugar in the blood. Hyperglycaemia can cause vomiting, hunger and thirst, vision problems, and other complications. Hypoglycaemia is often considered more dangerous, with confusion, irritation, and blurred vision some of the symptoms. It can cause serious problems if left untreated, such as seizures and unconsciousness, which is why monitoring blood sugar levels is important.