Glucose: Test Types, Levels and Health Risks

What is Glucose?

Glucose is a type of carbohydrate, a simple sugar that the body uses for energy.

When consuming foods containing carbohydrates, the body breaks them down into glucose. This glucose enters the bloodstream and is carried to the cells, where it’s used for energy.

The body has a system to regulate the amount of glucose in the blood, mainly involving the hormone insulin, which helps cells absorb glucose. When this system doesn’t work properly, it can lead to high or low blood sugar levels, which can affect health.

Importance of Monitoring Glucose Levels

Monitoring the glucose levels can tell a lot about health. Here are some reasons why it’s important:

• Preventing Health Problems: Abnormal glucose levels can lead to serious health issues. High glucose levels over time can cause diabetes, which can lead to complications like heart disease, kidney problems, and nerve damage. Low glucose levels can cause dizziness, confusion, and even loss of consciousness.
• Managing Diabetes: For people with diabetes, regular monitoring helps manage the condition. It allows them to adjust their diet, exercise, and medication to keep their glucose levels in check.
• General Health: Even for individuals without diabetes, knowing their glucose levels can be a part of a regular health check-up. It helps them understand how their body processes food and can alert them to potential problems before they become serious.

Types of Glucose Tests

Blood Glucose Tests

There are several types of blood glucose tests, each serving a different purpose. Here’s a closer look at the main ones:

This test measures the blood sugar after fasting. This test is typically conducted in the morning before having breakfast.

• Purpose: This test is crucial for diagnosing diabetes and prediabetes. Since it measures blood sugar after an overnight fast, it provides a clear baseline level of glucose without the influence of recent food intake. For individuals with diagnosed diabetes, it helps in monitoring the effectiveness of their diabetes management plan, including medication, diet, and lifestyle changes.
• Normal Range:  According to the World Health Organization (WHO), the expected values for normal fasting blood glucose concentration are between 70 mg/dL and 100 mg/dL.

This test measures the blood sugar at any time of the day, regardless of when an individual last ate.

• Purpose: It’s used for a quick assessment of blood sugar levels, especially when diabetes symptoms are present, such as increased thirst, frequent urination, or fatigue. In emergency situations, this test provides immediate information about a person's blood glucose levels, which is essential for making rapid medical decisions.
• Normal Range: According to the American Diabetes Association (ADA), levels should ideally be below 200 mg/dL. 

This test measures the blood sugar before and after drinking a sugary liquid.

• Purpose: OGTT is essential for diagnosing gestational diabetes during pregnancy, type 2 diabetes, and prediabetes by measuring how the body processes glucose. It also helps assess insulin resistance, providing detailed insights into glucose metabolism for effective diabetes management.
• Normal Range: For non-pregnant individuals, blood sugar should be below 140 mg/dL two hours after drinking the liquid. For pregnant women, according to Cleveland Clinic, it should be below 155 mg/dL two hours after taking the drink.

This test measures the average blood sugar levels over the past 2-3 months.

• Purpose: The Hemoglobin A1c test measures average blood sugar levels over 2-3 months, crucial for diagnosing diabetes and prediabetes, evaluating treatment effectiveness, and predicting complications. It provides a comprehensive view of glucose control, aiding healthcare providers in improving management and preventing issues.
• Normal Range: A normal A1c level is below 5.7% and for people with diabetes, the goal is often below 7% as mentioned in WebMD.

Each of these tests provides valuable information about glucose levels, helping individuals and their healthcare providers make informed decisions about their health.

Urine Glucose Tests

Urine tests can also provide information about glucose levels. Here are the main types:

This test measures the amount of glucose in urine.

• Purpose: It’s used when blood tests aren’t available, though it’s less accurate. High levels of glucose in the urine can indicate diabetes.
• Normal Range: Normally, there should be little to no glucose in urine.

Similar to the blood OGTT, this test involves drinking a sugary liquid and then measuring glucose in urine over a few hours.

• Purpose: It’s less common but can be used in specific situations where blood tests aren’t feasible.
• Normal Range: Glucose should not normally appear in the urine after the test.

Test Preparations

Preparing for Blood Glucose Tests

Getting ready for a blood glucose test can help ensure accurate results.

• Fasting Requirements: For tests like fasting blood glucose and OGTT, Healthline advises avoiding consumption of any food or beverages, except water, for 8 hours beforehand.
• Medication Adjustments: Check with a doctor about any medications being taken. Some might need to be paused before the test.
• Physical Activity: Avoid strenuous exercise the day before the test, as it can affect glucose levels.
• Hydration: Drink plenty of water unless told otherwise. Staying hydrated can make it easier to draw blood.
• Scheduling: Try to schedule the test for the morning. This makes fasting easier and helps get accurate results.

Preparing for Urine Glucose Tests

Urine glucose tests are straightforward, but a little preparation can make them go smoothly:

• Hydration Requirements: Drink plenty of water the day before the test to ensure a good sample can be produced.
• Dietary Considerations: Fasting might not be necessary, but follow any specific instructions from the doctor.
• Timing: Some tests require samples at specific times. Ensure you know when to collect your urine.
• Sample Collection: Use the provided container and follow instructions on how to collect a clean, midstream sample. This helps avoid contamination.
• Labeling: If multiple samples are provided, label them correctly with the time and date of collection.

Interpreting Test Results

Blood Glucose Test Results

Understanding blood glucose test results is key to managing the health:

• Normal: 70-100 mg/dL
• Prediabetes: 100-125 mg/dL
• Diabetes: 126 mg/dL or higher

• Normal: Below 200 mg/dL
• Diabetes: 200 mg/dL or higher

• Normal: Below 140 mg/dL (2 hours after the drink)
• Prediabetes: 140-199 mg/dL
• Diabetes: 200 mg/dL or higher

• Normal: Below 5.7%
• Prediabetes: 5.7% to 6.4%
• Diabetes: 6.5% or higher

Note: Test results should always be interpreted by a healthcare professional. The information provided by glucose tests is crucial but should be considered alongside other medical evaluations and history. Do not make any health decisions based solely on test results without consulting a qualified healthcare provider.

Urine Glucose Test Results

Interpreting urine glucose test results can help to understand the body’s glucose levels:

• Normal Results: Little to no glucose in urine.
• Abnormal Results: The presence of glucose may indicate diabetes or other health issues.

How to Read The Test Results

To gain a thorough understanding of glucose levels, it’s important to seek guidance from a healthcare provider. They can explain the results in detail and provide personalized advice based on health conditions.

Additionally, for a detailed explanation of glucose levels and personalized health insights, urine or blood test results can be uploaded to the Docus Lab Test Interpretation tool. However, always consult a professional before taking any action.

Technological Advancements in Glucose Monitoring

Technology has significantly advanced in glucose monitoring, making it easier and more convenient to track blood sugar levels. 

CGM systems have transformed glucose management. Unlike traditional finger-prick tests, CGM systems use a small sensor placed under the skin to measure glucose levels continuously, day and night. 

This sensor transmits data to a wearable device or smartphone, providing real-time insights into glucose trends. CGM systems alert users to high or low glucose levels, enabling immediate action. These systems improve glucose management and reduce the need for painful finger pricks, making diabetes management more comfortable and efficient.