What Is a Blood Test?

By taking and testing a small sample of a person’s blood, doctors can check for many kinds of diseases and conditions. Blood tests help doctors check how the body’s organs are working and see if medical treatments are helpful.

To help your child get ready for a blood test, find out if they need to fast (not eat or drink) or should stop taking medicines before the test. Explain what to expect during the test. If your child is anxious about it, work together on ways to stay calm.

What Is a Comprehensive Metabolic Panel (CMP)?

The comprehensive metabolic panel (CMP) is a blood test that gives doctors information about the body's fluid balance, levels of electrolytes like sodium and potassium, and how well the kidneys and liver are working.

Why Are Comprehensive Metabolic Panels Done?

A CMP is done to learn information about the levels of:

• Glucose, a type of sugar used by the body for energy. High glucose levels may point to diabetes.
• Electrolytes:
  • Calcium, which plays an important role in how muscles and nerves work.
  • Sodium, potassium, carbon dioxide, and chloride, which help control the body's fluid levels and its acid-base balance. Normal levels of these electrolytes help keep cells in the body working as they should.
• Blood urea nitrogen (BUN) and creatinine, which are waste products filtered out of the blood by the kidneys. These levels show how well the kidneys are working.
• Albumin and total protein, which are needed to build and maintain muscles, bones, blood, and organ tissue. Low levels may be seen with liver or kidney disease, or nutritional problems.
• Liver tests: Alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin. When these levels are high, it can be a sign of a problem with the liver.

What if I Have Questions?

If you have questions about the CMP, or what the test results mean, talk to your doctor.