Serum/plasma mass concentration of glucose (24-hour profile)

This test is done to show how your blood sugar rises and falls across a full day and night, including during meals, physical activity, and sleep. It helps your doctor see patterns that a single fingerstick reading can miss, so diabetes or prediabetes can be diagnosed, monitored, and treated more precisely.

Your healthcare provider may order this test if you have diabetes, prediabetes, or if you’re at risk for blood sugar-related complications. It can also help assess how well your current treatment plan is working or identify patterns in your glucose levels that might need adjustment.

A small, wearable sensor placed just under the skin measures glucose in the fluid between your cells every few minutes throughout the day and night. The readings are sent wirelessly to a recording device or smartphone app, creating a continuous glucose profile that your care team can later review and interpret.

Blood is collected at scheduled intervals (typically every 2–4 hours) to measure glucose concentration in your serum or plasma. The results are analyzed to create a profile of your glucose levels throughout the day.

No lab visits or traditional blood draws are needed. A member of our staff cleans a small spot on the back of your upper arm and gently inserts a tiny, flexible sensor about the size of a grain of rice. The sensor stays in place for the entire 24-hour period and collects your samples automatically and comfortably.

You’ll need to fast for a specified period before starting the test (usually overnight). Blood samples are drawn via a small needle at designated times, often with a catheter inserted for convenience. You may be asked to keep a food diary or track activity to ensure accurate results.

Before the test, tell your doctor about all medicines, vitamins, and supplements you take, since some can affect glucose readings. You do not need to fast ahead of time. You will be asked to follow your normal daily routine and to record your meals, exercise, and sleep times so your results can be interpreted accurately.

Prepare by avoiding sugary foods/drinks before the first draw. Stay hydrated but avoid caffeine or alcohol. Wear comfortable clothing and bring any medications you take daily. Follow your provider’s specific instructions for timing and fasting.