What can cause secondary diabetes?

Secondary diabetes occurs as a result of another underlying condition or specific external factor, rather than as a primary metabolic disorder like type 1 or type 2 diabetes mellitus. The correct answer highlights that certain medications can lead to secondary diabetes as an adverse effect, even when they are administered correctly. This includes medications such as corticosteroids, which can increase blood glucose levels, causing a form of diabetes that is secondary to the use of these substances.

In contrast, a high carbohydrate intake can indeed affect blood sugar levels but does not directly cause secondary diabetes as a result of another underlying condition or medication. Excessive exercise typically promotes healthy glucose metabolism and can lower blood sugar levels, making it an unlikely cause of secondary diabetes. Therefore, when considering the causes of secondary diabetes, the focus on medications explicitly illustrates a route through which diabetes can arise due to external medical treatment.