Health Library

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 Hemoglobin Test?

Hemoglobin (HEE-muh-glow-bin) is a protein inside red blood cells that carries oxygen. A hemoglobin blood test helps doctors check the level of red blood cells. Red blood cells deliver oxygen to the different parts of the body.

Why Are Hemoglobin Tests Done?

Doctors will order a hemoglobin test to check for low or high levels of red blood cells. They might do this as part of a routine checkup to screen for problems and or because a child isn’t feeling well. Having a low number of red blood cells is called anemia. When the level is high, it’s called polycythemia (pol-ee-sy-THEE-me-uh).

What if I Have Questions?

If you have questions about the hemoglobin test or what the results of the test mean, speak with your doctor.