Final answer:
Hyperglycemia in a well-controlled individual can be triggered by infections or illness, which increases blood glucose and promotes microorganism growth. Other factors include insulin resistance, renal dysfunction, and the management of type 2 diabetes with lifestyle changes and medication.
Step-by-step explanation:
In a person who has previously maintained good glycemic control, hyperglycemia can be precipitated by various factors, one of which is infections or illness. When a person is infected, there can be an increased glucose concentration in the blood over a longer duration, which facilitates the growth of microorganisms and delays wound healing and surgical recovery. Detecting excessive insulin antagonists and dealing with certain renal dysfunctions can also lead to hyperglycemia. In total renal failure, for example, there is relative hyperglycemia because glucose is neither filtered nor excreted well. Additionally, management of type 2 diabetes often involves lifestyle changes, potentially supported by medications, to achieve good glycemic control and prevent hyperglycemia.