What Is a Follicle-Stimulating Hormone Level Test?
hormone (FSH) is an important part of the reproductive system. It’s
responsible for the growth of ovarian follicles. Follicles produce estrogen and
progesterone in the ovaries and help maintain the menstrual cycles in women. In
men, FSH is a part of the development of the gonads as well as sperm
The FSH test measures
the level of FSH found in your blood. Your doctor will order an FSH test to
find the underlying cause of symptoms affecting the reproductive system.
The Purpose of the FSH Level Test
An FSH test is a simple blood test. Women might be asked to have
this test done at a specific point in their menstrual cycle, usually the first
couple of days.
FSH Test for Women
In women, the most common reasons for an
FSH test include:
- assessing infertility problems
- assessing irregular menstrual cycles
- diagnosing disorders of the pituitary gland or
diseases involving the ovaries
FSH Test for Men
In men, an FSH test may be done to:
- evaluate a low sperm count
- assess hypogonadism or gonadal failure
- assess testicular dysfunction
FSH Test for Children
An FSH test might be used to determine if a child is experiencing
precocious puberty, which is early puberty. An FSH test may also be used to
determine if a child is experiencing delayed puberty. This occurs when sexual
features or organs don’t develop when they should.
What Should My Doctor Know Before I Take the Test?
Talk to your doctor about any prescription or nonprescription
medications, dietary supplements, and vitamins you’re taking before any medical
test is performed. You should tell your doctor about any types of birth control
you use, such as the pill, an intrauterine device, or the patch, because this
may play a role in your test results.
You should also discuss any existing medical disorders with your
doctor, such as the following:
- uncontrolled thyroid disease
- sex-dependent hormone tumors
- ovarian cysts
- unusual vaginal bleeding
These conditions may be associated with FSH levels.
What Happens During the Test?
The test for the FSH level is simple and involves the following
- A healthcare provider will tie a tourniquet
above the site where the blood will be taken. Blood is usually taken from the arm.
- They’ll clean and sterilize the site with an antiseptic
and insert a needle directly into your vein.
- Most people feel a few moments of sharp pain initially,
but this will quickly fade as the blood is drawn.
- They’ll remove the needle within a few minutes
and then ask you to apply pressure to the site with a cotton ball or small
- They’ll place a bandage on the site.
What Risks Are Associated with the Test?
With any procedure, a small amount of risk is involved. Slight
- vasovagal syncope, or fainting at the sight of
- an infection
- a hematoma
- redness at the needle site
Understanding Your Results
FSH levels vary based on gender and age. They also vary depending
on where a woman is in her monthly cycle. Each lab has a slightly different
reference range. You should discuss your results with your doctor.
High FSH Levels
High FSH Levels in Women
If you’re a woman with high FSH levels, this may indicate:
- a loss of ovarian function, or ovarian failure
- polycystic ovarian syndrome, which is a
condition in which a woman’s hormones are out of balance, causing ovarian cysts
- a chromosomal abnormality, such as Turner’s
syndrome that occurs when part or all of one of a woman’s X chromosomes is
An increase in FSH may also indicate a reduction in the
production of good quality eggs and embryos for fertilization. A common reason
for this is your age. As you age, your fertility starts to decline and fewer
eggs mature in your ovaries. The quality of the eggs that remain is lower than
during earlier years.
The FSH test may be used with other tests that look at the levels
of luteinizing hormone, estradiol, and progesterone to determine a woman’s
ovarian reserve. The term “ovarian
reserve” refers to a woman’s age-related fertility potential. A
high FSH level means your chances of becoming pregnant may be lower than
expected for your age. This doesn’t mean you have no chance of conceiving, but you
may have more difficulty and need infertility treatment.
High FSH Levels in Men
If you’re a man with high FSH values, this may indicate:
- Klinefelter’s syndrome, which is a rare
condition in men caused by an extra X chromosome that can affect male
- testicles that
are absent or not functioning properly
- testicles that have been damaged by a disease
such as alcohol dependence
- testicles that have been damaged by treatments
such as X-rays or chemotherapy
High FSH Levels in Children
High FSH levels in children may mean that puberty is about to
Low FSH Levels
Low FSH values may indicate that:
- a woman isn’t producing eggs
- a man isn’t producing sperm
- the hypothalamus or pituitary gland, which
are the hormone control centers in the brain, aren’t functioning properly
- a tumor is interfering with the brain’s ability
to control the production of FSH
Stress and being severely underweight can affect FSH values.