Blood sugar, also known as glucose, is the primary sugar circulating in your bloodstream. It serves as the body’s main source of energy, fueling everything from cellular functions to physical activity. Glucose comes from the foods you eat, particularly carbohydrates, and is transported to cells with the help of insulin, a hormone produced by the pancreas. Understanding your blood sugar levels and what they signify is important for maintaining overall health.
Understanding Blood Sugar Ranges
Blood sugar levels are categorized into three main ranges: normal, prediabetes, and diabetes, based on specific tests. A fasting plasma glucose (FPG) test, taken after at least eight hours without food, indicates normal levels below 100 milligrams per deciliter (mg/dL). Prediabetes is identified by FPG levels between 100 and 125 mg/dL, while a reading of 126 mg/dL or higher indicates diabetes.
The 2-hour post-meal glucose test or oral glucose tolerance test (OGTT) is another assessment. Normal levels are less than 140 mg/dL. Prediabetes is diagnosed when the 2-hour reading falls between 140 and 199 mg/dL. A result of 200 mg/dL or higher suggests diabetes.
The A1C test provides an average of your blood sugar levels over the past two to three months. A normal A1C is below 5.7%. Prediabetes is indicated by an A1C between 5.7% and 6.4%, and diabetes is diagnosed at 6.5% or higher. These ranges serve as general guidelines, and a single reading does not always provide a definitive diagnosis.
What a 137 mg/dL Reading Means
A blood sugar reading of 137 mg/dL carries different implications depending on when the test was performed. If this reading was taken after at least eight hours of fasting, it falls into the diabetic range. Fasting blood sugar levels of 126 mg/dL or higher are considered diagnostic of diabetes. This indicates that the body may not be effectively regulating glucose during periods without food.
Conversely, if 137 mg/dL was measured approximately two hours after a meal or during an oral glucose tolerance test, it is within a healthy range. Such a reading would be considered a normal fluctuation as the body processes carbohydrates.
If 137 mg/dL is a random blood sugar reading, taken at any time of day, it is not immediately concerning. Random glucose levels can fluctuate, and diabetes is indicated by a random reading of 200 mg/dL or higher, often accompanied by symptoms. Consistent readings at this level, regardless of timing, warrant further investigation to determine underlying causes.
Common Influences on Blood Sugar
Blood sugar levels can fluctuate throughout the day due to various factors. Recent food intake, especially carbohydrates, directly influences glucose levels, causing them to rise after meals. Physical activity tends to lower blood sugar as muscles use glucose for energy. Conversely, periods of inactivity can contribute to higher levels.
Stress, both physical and emotional, can also elevate blood sugar. The body releases hormones in response to stress that can increase glucose production. Illnesses and infections prompt similar hormonal responses, leading to temporary increases in blood sugar. Certain medications, such as steroids, are known to raise blood glucose levels. Dehydration and hormonal changes (e.g., menstrual periods, menopause) can also play a role.
When to Consult a Healthcare Professional
An elevated blood sugar reading, such as 137 mg/dL, warrants a discussion with a healthcare professional. While a single reading might be influenced by temporary factors, consistent high levels can indicate an underlying condition. A doctor can perform additional tests to confirm a diagnosis.
These tests provide a more complete picture of your average blood sugar control and how your body processes glucose. It is also important to discuss any personal risk factors, such as family history of diabetes, and other symptoms you might be experiencing. Symptoms like increased thirst, frequent urination, unexplained fatigue, or blurred vision should always prompt medical attention. A healthcare professional can guide you on the appropriate next steps and management strategies.