Renal Function Panel

Glucose

Glucose is the sugar your body uses as its main source of energy. The level in your blood at the moment of the draw rises after eating and falls between meals, so a fasting sample is the usual way to read it. It is commonly checked when blood sugar or diabetes is a question.

Why it’s measured: To see your blood sugar at the time of the draw, ideally after fasting.

Blood urea nitrogen (BUN)

Urea is a waste product your liver makes when it breaks down protein, and your kidneys clear it into urine. BUN measures the urea nitrogen in your blood. It can shift with hydration, the protein in your diet, and how well the kidneys are filtering, so it is read with creatinine.

Why it’s measured: To help gauge kidney filtering and hydration, read alongside creatinine.

Creatinine

Creatinine is a waste product made at a fairly steady rate by your muscles and removed by your kidneys. Because the kidneys clear it, the level in your blood helps show how well they are filtering. Muscle mass, age, and sex affect the usual level, so it is read in context.

Why it’s measured: A common measure of kidney filtering, and the basis for eGFR.

Estimated glomerular filtration rate (eGFR)

eGFR is not measured directly. The lab calculates it from your creatinine result along with your age and sex to estimate how much blood your kidneys filter each minute. It gives a clearer view of kidney function than creatinine alone, and a provider reads it over time.

Why it’s measured: To estimate kidney filtering from your creatinine, age, and sex.

BUN/creatinine ratio

This ratio compares your BUN result with your creatinine result. The lab calculates it from the two numbers rather than measuring it separately. A provider may look at it to help sort out whether a change in kidney numbers relates to hydration, diet, or kidney function.

Why it’s measured: Adds context when BUN or creatinine is outside the reference range.

Sodium

Sodium is an electrolyte that helps control the balance of water in and around your cells and supports nerve and muscle function. Blood sodium reflects your fluid balance as much as the salt you eat, and it can shift with hydration, some medicines, and conditions that affect the kidneys or hormones.

Why it’s measured: A core electrolyte for checking fluid and electrolyte balance.

Potassium

Potassium is an electrolyte that your nerves and muscles, including your heart, need to work properly. Your kidneys keep the level in a narrow range. It can be affected by kidney function, some medicines such as diuretics, and how the sample is handled, so it is read with other results.

Why it’s measured: Muscles and the heart depend on potassium staying in a narrow range.

Chloride

Chloride is an electrolyte that works with sodium to keep fluids and electrical charges in balance in your body. It usually moves in step with sodium. It is rarely read on its own and is most useful alongside sodium, potassium, and carbon dioxide in an electrolyte or metabolic panel.

Why it’s measured: Read with sodium and CO2 to check fluid and acid-base balance.

Carbon dioxide (CO2, bicarbonate)

This result mostly reflects bicarbonate, a form of carbon dioxide that helps keep your blood from becoming too acidic or too alkaline. Your lungs and kidneys work together to hold it steady. It is read with the other electrolytes to look at your body’s acid-base balance.

Why it’s measured: A window on acid-base balance, read with the other electrolytes.

Calcium

Calcium is a mineral your bones, muscles, nerves, and heart all rely on. Hormones, including parathyroid hormone and vitamin D, keep the level in your blood tightly controlled. Because part of blood calcium travels attached to albumin, a provider often reads it alongside your albumin result.

Why it’s measured: To check a mineral that bones, nerves, and muscles all depend on.

Phosphate (phosphorus)

Phosphate is a mineral that works with calcium to build bones and teeth and helps cells store energy. Your kidneys and hormones help control the level. On its own it says little, so a healthcare provider reads it together with your calcium and kidney results.

Why it’s measured: Read with calcium and kidney results to check mineral balance.

Albumin

Albumin is the main protein your liver makes. It helps keep fluid inside your blood vessels and carries hormones, vitamins, medicines, and minerals such as calcium through your blood. Levels can change with liver or kidney conditions, hydration, and longer-term illness.

Why it’s measured: Reflects liver protein production and fluid balance in the blood.

• Each marker next to the lab’s reference range
• Explained in plain language
• A licensed clinician reviews your order and, if appropriate, orders the test.
• A lab report you can download and share

An out-of-range result, such as potassium, can need prompt follow-up with a healthcare provider, who reads the full set and any trends.