Hyperglycemia, or high blood sugar, occurs when glucose levels in the bloodstream rise above normal ranges. For someone not diagnosed with diabetes, a fasting blood glucose level exceeding 125 mg/dL, or a level greater than 180 mg/dL two hours after eating, indicates hyperglycemia. Consistently elevated blood sugar can lead to significant health complications, potentially damaging nerves, blood vessels, tissues, and organs. Understanding the factors that cause blood glucose to rise is important for managing health and preventing long-term adverse effects.
Underlying Health Conditions
Chronic health conditions represent a major cause of hyperglycemia. Diabetes mellitus is the most common condition, characterized by persistently high blood sugar due to issues with insulin production or utilization. Type 1 diabetes is an autoimmune disorder where the body’s immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. This results in little to no insulin production, causing glucose to accumulate.
Type 2 diabetes arises when the body either does not produce enough insulin or cannot effectively use the insulin it produces, known as insulin resistance. Cells in muscles, fat, and the liver become less responsive to insulin, leading to glucose remaining in the blood. Gestational diabetes is a temporary form of hyperglycemia that develops during pregnancy, typically in the second or third trimester. Hormones from the placenta can interfere with insulin’s effectiveness, making blood sugar management challenging.
Disorders affecting the pancreas, beyond diabetes, can also impair its ability to produce insulin. Conditions like chronic pancreatitis, an inflammation of the pancreas, can damage insulin-producing cells, leading to hyperglycemia. Cystic fibrosis, a genetic disorder, can cause excessive mucus buildup that scars the pancreas, similarly affecting insulin production. Pancreatic cancer can also damage these cells, contributing to hyperglycemia.
Certain hormonal disorders can disrupt glucose regulation by interfering with insulin’s action or directly raising glucose. Cushing’s syndrome, characterized by excessive cortisol levels, increases glucose production and impairs insulin sensitivity in tissues like the liver and muscles. Acromegaly, a condition of excess growth hormone, also leads to higher glucose levels and insulin resistance. Hyperthyroidism, an overactive thyroid, can accelerate metabolism, increase glucose absorption from the intestines, and promote insulin resistance, making glucose control more difficult.