What are the health effects associated with hyperglycemia?

There are many.: Acute effects of hyperglycemia can be fatigue, blurred vision, excessive urination and thirst. Over time one may lose weight abnormally. Long term hyperglycemia leads to the microvascular complications of diabetes. These are diabetic retinopathy and possible vision loss or blindness, neuropathy and increased risk of amputation of a lower limb, and nephropathy possibly leading to kidney dialysis.

Risk of high glucose: Uncontrolled high blood glucose increase risk of all diabetic complications