Whether you’re going to see a doctor for a routine checkup or you’re admitted to the hospital, a basic metabolic panel is a combination of tests that can help a doctor assess important functions in your body.

These tests can be used to identify changes in fluid balance, electrolyte levels, sugar metabolism, and kidney function.

This article will take an in-depth look at a basic metabolic panel, why it’s performed, and what your results may indicate.

Fast facts
  • A basic metabolic panel tests levels of eight substances in the blood, which measure electrolyte balance, sugar metabolism, and kidney function.
  • Abnormal test results might be used to diagnose kidney disease, diabetes, or lung disease, among other conditions.
  • A doctor can provide more information about what your test results mean and whether additional treatment is necessary.

A basic metabolic panel may be part of a routine checkup and also may be used to diagnose certain medical issues, including diabetes and kidney or lung problems.

The tests that make up the basic metabolic panel are blood (serum) tests for:

  • BUN (blood urea nitrogen): This measures the amount of nitrogen in the blood in order to determine your kidney function.
  • Creatinine: This can tell the doctor how your kidneys are functioning.
  • Glucose: This checks your blood sugar levels — abnormally high or low glucose levels could indicate a range of issues.
  • CO2 (carbon dioxide or bicarbonate): This references lung and kidney function.
  • Calcium: This can help determine if there is a kidney bone or parathyroid problem (a gland in the neck).
  • Sodium: This is one of the salts in the body that reflects the body’s water balance.
  • Potassium: This is another salt in the body.
  • Chloride:This is an electrolyte that helps maintain fluid and acid-base balance.

Your sodium, potassium, and chloride levels will be tested as part of your electrolyte panel. Electrolyte balance is essential to the healthy functioning of the muscular, cardiovascular, and nervous systems.

Below are approximate healthy ranges for each test included in the basic metabolic panel. Depending on the laboratory doing the test, these reference values may vary.

TestHealthy rangeCategory
BUN (blood urea nitrogen)6-20 mg/dL (milligrams per deciliter of blood)kidney test
creatinine0.6-1.3 mg/dLkidney test
glucose70-100 mg/dLsugar metabolism
CO2 (carbon dioxide or bicarbonate)23-29 mEq/L (milliequivalent units per liter of blood)electrolyte panel
Ca+ (calcium)8.5-10.2 mg/dLelectrolyte panel
Na+ (sodium)135-145 mEq/Lelectrolyte panel
K+ (potassium)3.7-5.2 mEq/Lelectrolyte panel
Cl- (chloride)96-106 mEq/Lelectrolyte panel

The basic metabolic panel can give doctors a good idea as to whether you have any serious problems with:

This can help uncover a variety of medical issues, including:

  • kidney problems
  • lung problems
  • problems with insulin metabolism

More detailed tests will be ordered if any of these basic indicators are abnormal.

One advantage of a panel of tests is that many tests can be done with just one blood sample. It’s then divided up in a lab.

A small amount of your blood is needed to perform this panel of tests. The blood sample is obtained through “venipuncture.” A needle is inserted into a vein in your arm or hand. Blood is drawn through the needle into a tube and analyzed in a laboratory.

Sometimes, a doctor might recommend not eating or drinking anything for 8 hours before your test.

Otherwise, you do not need to do anything special before this test and should not stop taking medication unless a doctor tells you to.

When the blood is collected, you may feel some moderate pain or a mild pinching sensation. After the needle is removed, you may feel a throbbing sensation.

You’ll be instructed to apply pressure to the site where the needle entered your skin. A bandage will be applied and may need to remain in place to stop any bleeding. You should avoid using that arm for heavy lifting for the rest of the day.

There are some very rare risks involved in taking a blood sample, including:

  • lightheadedness or fainting
  • hematoma, a bruise where blood accumulates under the skin
  • infection, which is usually prevented if the skin is cleaned before the needle is inserted
  • excessive bleeding for a long period after the test may indicate a more serious bleeding condition and should be reported to a doctor

Abnormal test results may indicate a serious medical condition, such as kidney disease, diabetes, or lung disease.

Kidney tests

A high BUN level may indicate kidney disease. Other possible causes include congestive heart failure or hypovolemic shock.

This can increase your BUN, as can bleeding. A low BUN level may be due to insufficient protein in your diet. It may also occur in people who are pregnant or those with a small body type.

A high creatinine level may also be caused by kidney disease, pregnancy, intense physical activity, the use of certain medications, or a diet high in red meat. A low creatinine level may be due to muscle loss, severe liver disease, or a lack of protein in the diet.

Learn more: Kidney health and kidney disease basics »

Sugar metabolism

Fasting blood glucose levels can help to diagnose diabetes. You may have diabetes if your fasting blood glucose is over 126 mg/dL or higher. Other problems, such as hyperthyroidism and certain kinds of pancreatic cancers, involve high blood glucose.

Low blood glucose may indicate an underactive thyroid gland or liver disease. Low glucose can also occur when a person with diabetes consumes too much insulin or other diabetes medications.

Learn more: Understanding borderline diabetes: Signs, symptoms, and more.

Electrolyte panel

High bicarbonate or carbon dioxide levels may be caused by many conditions, including breathing problems, metabolic problems, Cushing’s syndrome, or hormonal problems.

Lower-than-normal levels can be caused by acidosis, kidney disease, or several kinds of poison toxicities.

Learn more: Cushing’s syndrome.

High serum calcium can be caused by problems with the parathyroid gland or certain types of cancer.

Low serum calcium levels can be caused by many conditions, including:

  • an underperforming parathyroid gland
  • kidney failure or liver disease
  • vitamin D deficiency
  • problems with your pancreas

High serum sodium may be due to various hormonal diseases, such as diabetes insipidus or Cushing’s syndrome.

A lower-than-normal sodium level may also be due to hormonal abnormalities, such as Addison’s disease or SIADH (syndrome of inappropriate hormone secretion). Low sodium may also be due to dehydration, vomiting, and heart, liver, or kidney failure.

Learn more: Addison’s disease.

High serum potassium often indicates kidney disease and other conditions like Addison’s disease or type 1 diabetes that is not well-controlled. Potassium is very important for muscle function. High potassium levels can cause problems with the electrical activity of the heart.

Low serum potassium may be due to bodily fluids loss, diuretic medications, excessive alcohol use, low dietary potassium intake, or certain hormonal problems. Low levels can cause an irregular heartbeat.

High chloride levels may indicate metabolic acidosis, where the kidneys are not removing enough acid from the body. High chloride levels can also be caused by dehydration or diarrhea, along with other conditions such as kidney disease.

Low chloride levels may be due to Cushing Syndrome, congestive heart failure, or dehydration. Metabolic alkalosis and a number of other abnormalities affect chloride levels as well.

These are all brief summaries of possible causes for abnormal test results. Talk to a doctor about each specific test in detail to learn more about what these levels may indicate.

Here are answers to additional questions about the basic metabolic panel.

What does a metabolic panel test for?

A basic metabolic panel tests levels of eight substances in your blood, including BUN, creatinine, glucose, carbon dioxide, and electrolytes. This can provide information about your body’s fluid balance and the function of your liver and kidneys.

Is fasting required for a basic metabolic panel?

You may sometimes need to avoid eating or drinking anything for at least 8 hours before your test. A doctor can provide more information about whether fasting is required before your test.

What is the difference between a basic and comprehensive metabolic panel?

A comprehensive metabolic panel includes the same eight tests as a basic metabolic panel. However, it also includes six additional tests, which can help assess protein levels and liver function.

A basic metabolic panel can be used to assess your body’s fluid balance and electrolyte levels and diagnose certain medical issues.

Abnormal levels in a basic metabolic panel can be caused by a wide range of health conditions and may indicate an issue with sugar metabolism, kidney disease, or lung problems.

A doctor can provide more details about how to interpret your test results and the best course of treatment to help correct any abnormalities.