Why is hyperglycemia more dangerous than diabetic ketoacidosis?

It is not: It depends on the degree of hyperglycemia but diabetes ketoacidosis (DKA) is very dangerous and potentially "deadly." hyperglycemia can sometime be treated with increasing fluid intake, increasing Insulin or oral medication dosages (outpatient) whereas DKA patients are typically hospitalized for IV fluid and IV Insulin treatment.

It isn't : Insulin deficiency causes hyperglycemia in people with diabetes. Mostly in type 1 patients, the longer the Insulin deficiency goes on, the higher the blood sugars might get. Eventually, the body makes ketones as an alternate fuel for heart and brain since glucose can't get into cells. The longer the ketosis lasts the more acid buildup which becomes dka. It is a medical emergency.