Blood Test: Estradiol



Blood Test: Estradiol


What It Is



An estradiol test measures the level of the hormone estradiol in the
bloodstream. Estradiol plays an important role in sexual development:
It's the most important form of the hormone estrogen. In sexually mature
females, it's produced mainly by the ovaries, and in smaller amounts by
the adrenal glands. Estrogen is also produced by the placenta during
pregnancy. Sexually mature males have much lower blood levels of
estradiol, which are produced by the testes and adrenal glands.

In young girls, estradiol levels are normally low. As puberty
approaches, usually between ages 8 and 14, the pituitary gland, located
just beneath the brain, secretes two hormones (luteinizing hormone, or
LH; and follicle-stimulating hormone, or FSH) that work together to
stimulate the ovaries to make estradiol. Increased estradiol production
is largely responsible for breast development, genital growth, and
changes in the distribution of body fat in pubescent girls.

Because human sex hormones work so closely with one another, doctors
often perform the estradiol test with tests for LH, FSH, testosterone
(the male sex hormone — but teen and adult females produce some, too),
and progesterone (the hormone that prepares the body for pregnancy).
Taken together, the results can often provide a more complete picture of
a person's sexual maturation status and help doctors diagnose diseases
causing sex hormone imbalances.

Why It's Done



Doctors may order an estradiol test if a girl appears to be entering
puberty earlier or later than expected. High levels are associated with
precocious (early) puberty, while low levels may indicate a delay in
sexual development.

Estradiol levels also give important information on the functioning
of the ovaries. This can help doctors evaluate menstrual problems,
including abnormal bleeding or missing periods. The test may also be
used in boys or girls to check for damage or disease of the testes,
ovaries, or adrenal glands.

Testing estradiol levels also can be used to monitor the progression
of a pregnancy, fertility treatments, or to evaluate menopause symptoms.

Preparation



No special preparations are needed for this test. On the day of the
test, it may help to have your child wear a short-sleeve shirt to allow
easier access for the technician who will be drawing the blood.Continue
The Procedure



A health professional will usually draw the blood from a vein. First,
the skin surface is cleaned with antiseptic, and an elastic band
(tourniquet) is placed around the upper arm to apply pressure and cause
the vein to swell with blood.

Then, a needle is inserted into a vein (usually in the arm inside of
the elbow or on the back of the hand) and blood is withdrawn and
collected in a vial or syringe. After the procedure, the elastic band is
removed. Once the blood has been collected, the needle is removed and
the area is covered with cotton or a bandage to stop the bleeding.
Collecting the blood for the test will only take a few minutes.

What to Expect



Collecting a sample of blood is only temporarily uncomfortable and
can feel like a quick pinprick. Afterward, there may be some mild
bruising, which should go away in a few days.

Getting the Results



The blood sample will be processed by a machine. The results usually are available within a few days.

Risks



The estradiol blood test is considered a safe procedure. However, as
with many medical tests, some problems can occur with having blood
drawn, such as:

• fainting or feeling lightheaded
  
• hematoma (blood accumulating under the skin causing a lump or bruise)
  
• pain associated with multiple punctures to locate a vein
  

Helping Your Child



Having a blood test is relatively painless. Still, many kids are
afraid of needles. Explaining the test in terms your child can
understand might help ease some of the fear.

Allow your child to ask the technician any questions he or she might
have. Tell your child to try to relax and stay still during the
procedure, as tensing muscles and moving can make it harder and more
painful to draw blood. It also may help for your child to look away when
the needle is being inserted into the skin.

If You Have Questions



If you have questions about the estradiol test, speak with your doctor.