Follicle-stimulating hormone: what it is and how it affects our body

Do you know the follicle-stimulating hormone (in English, FSH)? It is a hormone linked to fertility. Its levels vary in situations such as: fertility problems, pregnancy or being under hormone treatment, among others.

In this article we will see everything about this hormone: what are its functions, where it is produced, what are the "normal" levels of it during the different stages of the menstrual cycle, what implies abnormal levels (both low and high) of it and, finally, what the follicle-stimulating hormone test or examination consists of.

• Related article: "Types of hormones and their functions in the human body"

Follicle-stimulating hormone (FSH)

Follicle-stimulating hormone, also called follicle-stimulating hormone or follicle-stimulating hormone (FSH), is a type of gonadotropin hormone. This hormone is found in humans and also in other mammals.

Its function is essential in the reproductive cycle, and it participates in both sexes in growth and development..

Follicle-stimulating hormone is produced in the pituitary gland; the

hypophysis, also called the "pituitary gland," is a small gland located just below the brain, which produces different hormones, which travel to the bloodstream and carry out their functions.

Functions in the organism

What function does this hormone have in men and women? In the case of men, follicle-stimulating hormone is involved in the synthesis of sperm. In women, its function is related to the regulation of the maturation of the organism until the stage of puberty. In addition, in this sense, it is the hormone responsible for stimulating the synthesis of estrogens.

On the other hand, in the first phase of the women's menstrual cycle, follicle-stimulating hormone modulates oocyte maturation. Oocytes are female germ cells; that is to say, they are cells in a stage prior to that of the mature ovules (which end up becoming these).

In addition, follicle-stimulating hormone is a marker that allows the diagnosis of certain gynecological irregularities in women, in relation to infertility and menstruation (rules).

So, it's about a hormone closely linked to fertility, both in men and women. Its levels, as we will see later, allow us to determine if the sexual organs work well, or if there is a problem (with abnormal levels).

• You may be interested in: "The 4 types of sex cells"

levels

Follicle-stimulating hormone levels vary throughout life. To give you a general idea, before puberty, your levels range from 0 to 0.4 FSH units per liter of blood.

As we grow older and once we enter the stage of puberty, its levels increase. up to 0.3 and 10 units per liter of blood.

Menstrual cycle

Later, when we enter childbearing age, Follicle-stimulating hormone levels also vary during the menstrual cycle.. Within the menstrual cycle, we find three major phases or periods:

• The follicular phase (which occurs before ovulation): 2-10 units per liter of blood.
• The ovulatory phase (during ovulation): 8-20 units per liter of blood.
• The luteal phase (after ovulation): 2-8 units per liter of blood.

Menopause

Finally, In the menopausal stage, the levels of follicle-stimulating hormone increase exaggeratedly, being these between 25 and 135 units per liter of blood.

Abnormal levels of this substance

What happens when our follicle-stimulating hormone levels are abnormal? Various pathological situations can trigger this fact, such as: suffering from anorexia, being underweight, not ovulating, having a disorder of the pituitary gland or hypothalamus etc

On the other hand, in a situation of pregnancy follicle-stimulating hormone levels may also change abruptly or be abnormal.

1. elevated levels

Elevated levels of follicle-stimulating hormone may be at the base of specific situations that should be known, both in men and women.

1. 1. in women

In the case of women, high levels of FSH may indicate: a situation of menopause or postmenopause (whether mentioned), a premature menopause, when you are under hormonal treatment, if you suffer from ovarian syndrome polycystic, if you have Turner Syndrome (a genetic disorder that affects the development of girls, where the X chromosome is missing or incomplete), if you have any type of pituitary tumor, etc.

• You may be interested in: "Turner syndrome: symptoms, types, causes and treatment"

1.2. in men

In men, elevated FSH levels could indicate: castration, alcoholism, receiving chemotherapy, increased of testosterone, suffering from Klinefelter Syndrome, taking drugs that contain testosterone, andropause, etc

2. Low levels

On the other hand, low levels of the hormone in women indicate malfunction of the ovaries when producing eggs, pregnancy, anorexia nervosa, being treated with birth control pills or corticosteroids, etc.

On the other hand, in men, low levels of the hormone indicate the existence of one of these situations: reduced function of the pituitary gland (or hypothalamus), being under stress, being underweight or produce few sperm.

The follicle-stimulating hormone test

It is very common, especially among women, to perform a follicle-stimulating hormone test. What this test does is measure the amount we have of this hormone through a blood sample.

It is mainly used to assess ovarian function; this implies the evaluation of the degree of fertility in the woman. Typically, the follicle-stimulating hormone test is performed in assisted reproductive centers (although not only in these), where women show difficulties (with their partner, or not) to get pregnant.

What is the FSH test used for?

We have seen the usefulness of the FSH test to determine possible fertility problems, both in women and in men.

Specifically, the follicle-stimulating hormone test makes it possible to determine if the sexual organs, both female and (ovaries or testicles) are working properly, or if there is an underlying problem that makes it difficult for pregnancy. On the other hand, the test also makes it possible to confirm whether the woman is in the menopausal stage.

Beyond being performed in assisted reproduction centers, this test can also be requested by your gynecologist or endocrinologist.. Thus, other situations that allow this test to be evaluated are:

• Precocious or delayed puberty
• Causes of the absence of menstruation
• Causes of irregular menstruation
• General functioning of the pituitary gland
• Presence of a tumor in the pituitary gland
• Low sperm count in men
• Adequate egg production in women

Values

When the follicle-stimulating hormone test is performed, reference values ​​of the population are consulted, according to age and gender of the person in question. The phase of the menstrual cycle in which it is located is also taken into account.

Bibliographic references:

• Carlson, N.R. (2005). Behavioral physiology. Madrid: Pearson Education.
• Prieto-Gomez, B. and Velázquez-Paniagua, M. (2002). Reproductive physiology: gonadotropin-releasing hormone. Rev Fac Med UNAM, 45(6): 252-257.
• Rosenweig, M.R., Breedlove, S.M, and Watson, N.V. (2005). Psychobiology: An introduction to behavioral, cognitive, and clinical neuroscience. Barcelona: Ariel.