Contributed by – Healthians Team
What is the FSH test?
The FSH test measures the level of follicle-stimulating hormone in the blood. This hormone is associated with the production and development of eggs in women and sperm in men. The pituitary gland, a small organ located at the base of the brain, produces FSH. However, control of its production is a complex process involving the hypothalamus in the brain, the pituitary gland, and various hormones produced by the ovaries and testicles.
FSH plays a crucial role in sexual development and functioning.
In women, FSH controls the menstrual cycle and stimulates the growth of eggs in the ovaries. Its levels keep fluctuating throughout the menstrual cycle of a woman, reaching the peak right before ovulation, wherein an egg is released by the ovary.
In men, FSH controls the production of sperm and also promotes the production of androgen binding proteins. FSH levels in men stay relatively constant after puberty.
And in children, FSH levels rise shortly after birth and then begin to fall to very low levels. They begin to rise again before the beginning of puberty and the development of secondary sexual characteristics.
Having abnormal levels of FSH can lead to a variety of issues such as infertility, menstrual problems, low sex drive and early or late puberty.
Who should get tested?
A doctor may order the FSH test for a woman if:
- She has been unable to get pregnant after 12 months of trying.
- Her menstrual cycle is irregular.
- Her periods have stopped.
In a man, the FSH test is asked for when:
- He’s been unable to get his partner pregnant after 12 months of trying.
- His sex drive has decreased.
FSH test is also ordered for both men and women in case symptoms related to pituitary disorder are present. They include:
- Fatigue
- Weakness
- Weight loss
- Reduced appetite
The FSH test may be ordered for children if they seem to be entering puberty too early or too late.
Why is the FSH test needed?
The use of FSH depends on whether you are a man, woman or child.
In women it is often used to:
- Find the cause of infertility
- Find out if there’s any problem with ovarian function
- Understand the cause of menstrual problems
- Confirm the start of menopause or perimenopause
In men FSH test is used to:
- Find the cause of infertility
- Understand the reason behind low sperm count
- Find out if there’s an issue with the testicles
And in children, the FSH test is used to diagnose early or late puberty.
What does FSH test results mean?
Normal values of the FSH test are as follows:
Male –
- Before puberty – 0 – 5.0mIU/mL
- During puberty – 0.3 – 10.0 mIU/mL
- Adult – 1.5 – 12.4 mIU/mL
Female –
- Before puberty – 0 – 4.0 mIU/mL
- During puberty – 0.3 – 10.0 mIU/mL
- Menstruating women – 4.7 – 21.5 mIU/mL
- After menopause – 25.8 – 134.8 mIU/mL
Remember that these values are for your reference. Each lab may have slightly different reference ranges, hence test results from different labs may vary.
Having high FSH levels could have the following meaning –
Cause of high FSH in women:
- Loss of ovarian function
- Polycystic ovary syndrome
- Start of menopause or perimenopause
- Ovarian tumor
- Turner syndrome
Causes of high FSH in men:
- Damaged testicles
- Klinefelter syndrome
High FSH in children means that puberty has started or is about to start. If it is happening before the age of 9 and 10 then it could mean the presence of a central nervous system disorder or a brain injury.
Having low FSH levels in the blood could have the following causes:
Causes of low FSH in women –
- Low egg production by the ovaries
- Problem with the function of pituitary gland
- Problem with hypothalamus
- Being underweight
Causes of low FSH in men –
- Disorder of the pituitary gland
- Disorder of the hypothalamus
Low FSH in children means delayed puberty. It may be caused by –
- Disorder of the ovaries or testicles
- Turner syndrome in girls
- Klinefelter syndrome in boys
- Certain infection
- Hormone deficiency
- Eating disorder
How is the test done?
FSH test is a simple blood test wherein a small sample of blood is needed. It is usually drawn from a vein in the arm. The process is simple, quick and relatively painless. Although no kind of special preparation is needed for the test, a woman who has not gone through menopause may be asked to schedule her test at a specific time during her menstrual cycle.
