17-OH Progesterone

Normally, your adrenal glands use 17-OHP to make a hormone called cortisol. Cortisol helps control your energy levels, blood glucose (sugar), blood pressure, and your body's response to stress, illness and injury.

A 17-OHP test helps diagnose a group of uncommon, inherited genetic disorders that affect how well your adrenal glands make cortisol. These genetic adrenal gland disorders are called congenital adrenal hyperplasia (CAH). People with CAH have a change in a gene that causes the lack of an enzyme that your adrenal glands need to make hormones. The most common type of CAH is caused by a lack of an enzyme called 21-hydroxylase. 21-hydroxylase helps your adrenal glands use 17-OHP to make cortisol.

Without enough 21-hydroxylase, the adrenal glands struggle to make enough cortisol. As the adrenal glands work harder to do their job, they become enlarged and make abnormally high levels of 17-OHP. These high levels of 17-OHP are a sign of CAH with 21-hydroxylase deficiency. The adrenal glands use the extra 17-OHP to make larger than normal amounts of male sex hormones.

The results of a 17-OHP test help show whether you or your child have the most common type of CAH, which is caused by a lack of 21-hydroxylase.

If test results show a normal amount of 17-OHP, it means that you or your child probably do not have CAH with 21-hydroxylase deficiency. If you or your child has symptoms, the provider may order other tests to figure out the cause.

If test results show higher than normal levels of 17-OHP, you or your child probably has CAH. The provider may order other tests to learn more about how CAH is affecting you or your child.

If you or your child is being treated for CAH, decreasing levels of 17-OHP over time means that the treatment is working. Treatment for CAH may include medicines to replace the cortisol your body can't make. Other medicines may also be needed, depending on the type of CAH.