Blood glucose, or blood sugar, is the primary energy source for the body’s cells and organs. Glucose is absorbed from food and regulated by the hormone insulin, which moves it from the bloodstream into the cells. A reading of 133 milligrams per deciliter (mg/dL) is higher than what is typically considered normal. Interpreting this specific number requires immediate context, as its significance changes dramatically based on when the blood sample was taken.
Understanding Test Timing and Context
Glucose levels fluctuate constantly, making the timing of a blood draw necessary for accurate interpretation. A 133 mg/dL reading is classified differently depending on whether it was taken while fasting, after a meal, or at a random time. The most standardized measure is the Fasting Plasma Glucose (FPG) test, which requires no caloric intake for at least eight hours. This test is usually performed first thing in the morning.
The postprandial glucose level measures blood sugar one to two hours after a meal. Because food causes a temporary spike, the acceptable range for a postprandial reading is naturally higher than a fasting one. A random plasma glucose test is a blood draw taken at any point during the day, without regard for the last time a person ate.
Classifying a 133 Reading
If the 133 mg/dL result was taken in a fasting state (after an overnight fast of eight or more hours), it is significantly elevated. Normal fasting glucose is below 100 mg/dL. Readings between 100 mg/dL and 125 mg/dL are classified as Impaired Fasting Glucose, which indicates prediabetes.
A reading of 133 mg/dL exceeds the prediabetes range and meets the threshold for a provisional diagnosis of diabetes, defined as a fasting glucose of 126 mg/dL or higher. This result indicates dysregulated glucose metabolism, meaning the body is not effectively managing blood sugar without food intake. This finding warrants immediate follow-up testing with a healthcare provider to confirm the result.
If the 133 mg/dL reading was taken two hours after a meal (postprandial), the interpretation is different. For healthy adults, the glucose level two hours after eating should be less than 140 mg/dL. In this context, 133 mg/dL falls within the normal range, indicating effective glucose management.
If 133 mg/dL was a random reading taken at an arbitrary time, it is not used directly for diagnosis unless it is 200 mg/dL or higher. However, this elevated number suggests a need for further investigation, especially if the person has symptoms like increased thirst or frequent urination. Regardless of the timing, a 133 mg/dL reading requires professional medical attention and confirmatory tests.
Further Testing Required for Diagnosis
Because a single elevated reading is not sufficient for a definitive diagnosis, a physician will order confirmatory tests. The A1C test, or glycated hemoglobin, is commonly used because it shows average blood glucose levels over the preceding two to three months. This test measures the percentage of hemoglobin proteins coated with sugar. An A1C result between 5.7% and 6.4% indicates prediabetes, while 6.5% or higher confirms diabetes.
Another diagnostic tool is the Oral Glucose Tolerance Test (OGTT), which measures how well the body processes a large amount of sugar. The procedure involves a fasting blood draw, consuming a sweetened drink (75 grams of glucose), and then having blood drawn again two hours later. A two-hour result between 140 mg/dL and 199 mg/dL indicates Impaired Glucose Tolerance (prediabetes), while 200 mg/dL or greater confirms diabetes.
Actionable Steps Following a High Reading
While waiting for confirmatory tests, individuals can proactively begin making lifestyle adjustments, which should be discussed with a healthcare professional. Dietary modifications are a first step toward managing blood sugar. Focus on reducing simple carbohydrates, such as refined sugars and processed foods, to prevent sharp glucose spikes.
Aim for complex carbohydrates rich in fiber, like whole grains, legumes, and non-starchy vegetables. Fiber slows the rate at which sugar is absorbed, promoting a gradual release of glucose. Portion control is also an effective strategy to manage overall caloric and carbohydrate load.
Incorporating regular physical activity is effective for improving glucose regulation. Exercise increases insulin sensitivity, allowing the body’s cells to more efficiently use insulin to take up glucose from the blood. A goal of at least 150 minutes of moderate-intensity activity per week, such as brisk walking, is recommended.
Consistent bouts of exercise, like a 30-minute walk each day, help muscles utilize glucose for energy. Staying hydrated by drinking plenty of water also helps the kidneys flush out excess glucose through urine. These steps contribute to healthier blood sugar levels and may improve outcomes on subsequent diagnostic tests.