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 Estradiol?

Estradiol (ess-truh-DYE-ul) is a hormone that plays an important role in sexual development.

Why Are Estradiol Tests Done?

An estradiol test measures the level of the hormone estradiol in the bloodstream. Doctors may order the test if puberty starts earlier or later than expected.

Estradiol levels also give important information about how the ovaries are working. This can help doctors evaluate menstrual problems, including abnormal bleeding or missed periods.

The test also can check for damage or disease of the testes, ovaries, or adrenal glands.

Human sex hormones work closely with one another. So doctors might do an estradiol test along with blood tests that measure LH, FSH, testosterone, and progesterone (the hormone that prepares the body for pregnancy). Together, the results can give doctors a more complete picture of a child or teen's sexual maturation status.

Estradiol tests also can help doctors monitor a pregnancy or fertility treatments, and evaluate menopause symptoms.

What if I Have Questions?

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