Glucose in Serum (24-hour Profile)

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms of diabetes, such as frequent urination, excessive thirst, unexplained weight changes, or fatigue. It may also be used to monitor blood sugar control in people with diabetes or to check for conditions like hypoglycemia (low blood sugar) or prediabetes.

What to Expect Before the Test

You’ll typically fast for 8 to 12 hours before the test, but some centers may allow a small amount of water. Blood samples are collected at multiple time points (often including fasting, mid-morning, mid-afternoon, and overnight) to track glucose levels over time. Avoid strenuous activity or eating/drinking anything except water during this period.

What the Test Results Mean

Results show glucose levels at different times, helping identify patterns like spikes after meals, low levels overnight, or consistent high/low readings. Abnormal patterns may indicate diabetes, insulin resistance, or other metabolic disorders that need medical attention.

Common Causes of Abnormal Results

Elevated glucose levels may be due to diabetes, stress, infections, or certain medications. Low glucose levels could result from insulin overuse, certain medications, or hormonal imbalances. Always discuss results with your provider to determine the cause and next steps.