What Is a Testosterone Level Test?
A testosterone level test measures the amount of
testosterone in the blood and is reported as nanograms per deciliter (ng/dL).
It’s also known as a serum testosterone test.
Testosterone is an androgen, or a sex hormone, produced by
both males and females. It plays a role in puberty and fertility. It also
affects sexual desire.
In males, the testes produce most of the testosterone. In
females, the production of testosterone occurs mostly in the ovaries. Males
have higher levels of testosterone than females. Doctors believe that
testosterone has a significant influence on the development of many traits,
- increased muscle bulk
- higher bone mass
- physical strength
- body hair
However, the hormone plays an important role in women as
well, including their reproductive health and the ability to feel sexual
Do You Need a Testosterone Level Test?
Your doctor may order this test for a variety of reasons.
Testosterone in Males
One common reason to order this test is either early or
delayed puberty. The test may also be necessary if your doctor suspects you may
have low hormone levels. A low levels of testosterone in a male is also known
The symptoms of hypogonadism in a male include:
- decreased body hair
- decreased muscle mass
- a low sex drive
- erectile dysfunction
- the growth of breast tissue, or gynecomastia
Some other possible causes of having low testosterone
- delayed puberty
- testicular damage, which can be caused by
trauma, alcoholism, or the mumps
- a hypothalamic disease
- a pituitary disease
- a noncancerous pituitary tumor
A number of genetic diseases can also affect testosterone levels,
including Klinefelter’s syndrome, Kallmann’s syndrome, and myotonic dystrophy.
It’s also possible for a male to have too much testosterone.
High testosterone levels can be problematic. Too much of this hormone can be
the result of:
- early, or precocious, puberty
- hyperthyroidism, or overactive thyroid
- anabolic steroids
- congenital adrenal hyperplasia
- androgen insensitivity syndrome
- testicular tumor
- adrenal tumor
Testosterone in Females
Your doctor will usually order testosterone level tests if
you’re a female and they suspect you have a high level of this hormone. Too
much testosterone in a female can lead to:
- irregular or absent menstrual periods
- the development of facial and body hair
- a deepened voice
There are several reasons a female may have too much testosterone,
- polycystic ovarian syndrome
- congenital adrenocortical hyperplasia
- ovarian cancer or tumor
- adrenal tumor
Do You Prepare for a Testosterone Level Test?
Certain drugs can affect your testosterone levels and change
the results of a testosterone level test. It’s important to tell your doctor
about all medications you’re taking, including over-the-counter and
prescription drugs. Your doctor may ask you to stop certain drugs before your
Medications that may affect this test include:
- androgen therapy
- estrogen therapy
Your doctor may specify a time of day for your test. Because
hormone levels are highest in the morning, you may need to take this test
between 7 a.m. and 10 a.m.
Your doctor may also ask you to have repeat testing, which
can track hormone changes throughout the day.
Happens During a Testosterone Level Test?
A testosterone test requires taking a blood sample. This involves
the following steps:
- A healthcare provider will clean the area where
they will draw your blood. This is usually from a vein on the inside of the
elbow or the back of the hand.
- They’ll tie an elastic band around your upper
arm to make blood pool in the vein.
- They’ll insert a sterile needle into your vein
- Then, they’ll draw your blood into a tube.
- After collecting the blood, they’ll remove the
elastic band and needle from your arm.
- They’ll apply pressure to the insertion site to
stop bleeding and prevent bruising
- They’ll apply a bandage.
Having your blood taken may cause some pain or discomfort.
It may feel like a pricking or burning sensation. Relaxing your arm can help
ease the pain. You may continue to feel some throbbing after they remove the needle,
but this should go away quickly.
Your doctor will send your blood sample to a laboratory for
Are the Risks Associated with a Testosterone Level Test?
The risks of a blood test include:
- multiple puncture wounds from trouble finding a
- excessive bleeding
- a hematoma, which is a collection of blood under
- an infection
What Is the Long-Term Outlook?
When your doctor receives your test results, they’ll look
them over. If your testosterone level is higher or lower than normal, they’ll
try to determine any underlying medical conditions based on your results.
Your doctor will discuss your results with you and help you
understand what they mean. Any follow-up testing or treatment plans should be
discussed during an appointment with your doctor.