Hyperglycemia, or high blood sugar, is an elevated level of glucose in the bloodstream. While often associated with diabetes, hyperglycemia can occur in individuals without a diabetes diagnosis. It can arise from various underlying factors that disrupt the body’s normal glucose regulation.
Understanding High Blood Sugar
Blood glucose, or sugar, is the body’s primary energy source, derived from carbohydrates in food. After digestion, glucose enters the bloodstream. Insulin, produced by the pancreas, helps transport this glucose into cells for energy. When this system is disrupted, glucose can accumulate in the blood, leading to hyperglycemia.
Normal fasting blood glucose levels are below 100 milligrams per deciliter (mg/dL), and levels two hours after a meal are less than 140 mg/dL. Hyperglycemia is defined as a fasting blood glucose greater than 125 mg/dL or a post-meal level exceeding 180 mg/dL. Blood sugar is measured through blood tests, including finger-prick tests using a glucose meter or laboratory blood draws.
Causes of Non-Diabetic Hyperglycemia
Factors unrelated to a diabetes diagnosis can lead to elevated blood sugar. Physical stress from severe illness, infection, surgery, or trauma is a common temporary cause. During these events, the body releases stress hormones like cortisol and epinephrine, increasing glucose production and reducing insulin effectiveness, which leads to a temporary rise in blood sugar. Infections like pneumonia or urinary tract infections can also trigger this stress response.
Certain medications can elevate blood glucose levels. Corticosteroids, used for inflammation, can impede insulin synthesis and increase glucose production. Diuretics, some antipsychotics, beta-blockers, and immunosuppressants are other drug classes that may impair glucose metabolism or insulin sensitivity. These medication-induced elevations often resolve once the drug is discontinued or adjusted.
Hormonal imbalances can contribute to non-diabetic hyperglycemia. Conditions like Cushing’s syndrome, characterized by excessive cortisol production, directly affect blood sugar regulation. Polycystic Ovary Syndrome (PCOS) often involves insulin resistance, where the body’s cells do not respond effectively to insulin, leading to higher blood glucose.
Acute medical conditions, such as pancreatitis, can damage the insulin-producing cells in the pancreas, resulting in temporary or prolonged hyperglycemia. Gestational hyperglycemia, distinct from pre-existing diabetes, can occur during pregnancy. This condition typically resolves after childbirth but indicates an increased risk for developing type 2 diabetes later in life.
Prediabetes is a state where blood sugar levels are higher than normal but not yet high enough for a diabetes diagnosis. Individuals with prediabetes have a fasting blood glucose between 100 and 125 mg/dL, or an HbA1c between 5.7% and 6.4%. It is a risk factor for progressing to type 2 diabetes and can be caused by insulin resistance or insufficient insulin production.
Recognizing the Signs and When to Act
High blood sugar may manifest through noticeable symptoms, though these can sometimes be subtle. Indicators include increased thirst and frequent urination, as the kidneys try to eliminate excess glucose. Other signs include fatigue, blurred vision, and unexplained weight loss. Nausea or abdominal pain may also occur.
Seek medical attention if these symptoms are persistent or severe. While mild, temporary elevations might not require immediate intervention, sustained high blood sugar warrants professional evaluation. If symptoms progress to include vomiting, confusion, or a fruity odor on the breath, prompt medical care is advised, as these could indicate a more serious condition.
Diagnosis and Future Considerations
Diagnosing the cause of hyperglycemia involves medical tests. A fasting plasma glucose test measures blood sugar after an overnight fast. An oral glucose tolerance test (OGTT) assesses how the body processes sugar after consuming a glucose-rich drink. The HbA1c test provides an average blood sugar level over the preceding two to three months, offering insight into longer-term glucose control.
For instance, a fasting glucose between 100 and 125 mg/dL indicates prediabetes, while 126 mg/dL or higher on two separate occasions typically confirms a diabetes diagnosis. Individuals with prediabetes have an elevated risk of developing type 2 diabetes and cardiovascular disease. Follow-up and proactive lifestyle changes are often recommended. These include adopting a balanced diet focused on whole foods, regular physical activity, and weight management. Addressing the underlying cause, whether medication adjustment or managing acute conditions, is also important for normalizing blood sugar levels and mitigating future health risks.