Non-diabetic hyperglycemia is an elevated blood glucose level not caused by diabetes, says MedicineNet. Random blood glucose levels, where the blood is tested for glucose throughout the day, are between 70 and 125 milligrams per deciliter, while fasting blood glucose levels are less than 100 milligrams per deciliter.
Non-diabetic causes of hyperglycemia include inflammation of the pancreas or pancreatitis, pancreatic cancer, an overactive thyroid and Cushing's syndrome, according to MedicineNet. Cushing's syndrome is a condition where the cortisol levels in the blood are elevated.
Rare hormone-secreting tumors can also cause blood sugar levels to be high, says MedicineNet. These include glucagonomas, which are tumors that begin in the pancreas and secrete excessive amounts of the hormone glucagon, says Healthline. Tumors that secrete growth hormone also raise blood sugar levels, as do pheochromocytomas. Pheochromocytomas are tumors that arise from the adrenal glands, says Mayo Clinic. Though they are benign, they cause spikes in blood pressure as well as blood glucose.
Blood glucose levels can become abnormally high if the body is under great stress such as a serious illness, heart attack, stroke or other trauma, according to MedicineNet.
Medications can also raise blood sugar levels, states MedicineNet. These medications include birth control pills, beta-blockers, prednisone and phenothiazines. The way to treat non-diabetic hyperglycemia is to treat the underlying condition.