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 17-Hydroxyprogesterone?

The hormone 17-hydroxyprogesterone is a building block for making the hormone cortisol. Most cortisol (KOR-tuh-sol) is made in the adrenal cortex (the outer part of the two , located above the kidneys). Cortisol is called the "stress hormone" because it's secreted in larger amounts as part of the body's response to physical or emotional stress.

Some people’s bodies can’t make enough cortisol because they lack an enzyme in the adrenal glands. They'll have a buildup of 17-hydroxyprogesterone (hi-drok-see-pro-JESS-teh-rone) in the blood because it's not being converted to cortisol.

In kids, this most often is due to a genetic disorder called congenital adrenal hyperplasia (CAH).

Why Are 17-Hydroxyprogesterone Tests Done?

This test measures the amount of 17-hydroxyprogesterone in the blood. Usually, doctors order it to check for the most common type of CAH in infants and children. In some states, it's one of the routine screening tests done on newborns. 

The test also can help doctors monitor the treatment of children with CAH. Kids with any CAH symptoms would likely have the test done, along with other hormone tests to check adrenal (uh-DREE-nul) function.

What if I Have Questions?

If you have questions about the 17-hydroxyprogesterone test or what the results of the test mean, talk to your doctor.