Follicle stimulating hormone: what is it and how does it affect our body?

What is follicle stimulating hormone and how does it affect the functioning of the body?

Do you know follicle stimulating hormone (FSH)? It is a hormone linked to fertility. The levels of this hormone vary in situations such as: fertility problems, pregnancy situation 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 abnormal levels (both low and high) of it imply and, finally, what is the test or test for follicle-stimulating hormone.

Follicle Stimulating Hormone (FSH)

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

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

Follicle-stimulating hormone is produced in the pituitary gland; the pituitary gland, also called the "pituitary gland", is a small gland located just below the brain, which produces different hormones, which travel into the bloodstream and perform their functions.

Functions in the body

What is the function of this hormone 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 up to the puberty stage. In addition, in this sense, it is the hormone responsible for stimulating estrogen synthesis.

On the other hand, in the first phase of a woman's menstrual cycle, follicle-stimulating hormone modulates oocyte maturation.. Oocytes are female germ cells; that is, they are cells at a stage prior to that of mature eggs (which eventually develop into eggs).

In addition, follicle-stimulating hormone is a marker for diagnosing certain gynecological irregularities in women, in relation to infertility and menstruation (menstruation).

Thus, it is a hormone closely linked to fertility in both men and women.. Their levels, as we will see later, allow us to determine if the sexual organs are functioning well, or if there is a problem (in case of abnormal levels).

Levels

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

As we grow older and once we enter puberty, FSH levels increase to between 0.3 and 10.0 units per liter of blood. to between 0.3 and 10 units per liter of blood.

Menstrual cycle

Later, when we enter the fertile age, follicle-stimulating hormone levels also vary during the menstrual cycle.. Within the menstrual cycle, there are 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, follicle-stimulating hormone levels increase exaggeratedly, reaching between 25 and 25 units per liter of blood.These levels are between 25 and 135 units per liter of blood.

Abnormal levels of this substance

What happens when our follicle-stimulating hormone levels become abnormal? Various pathological situations can trigger this, such as: suffering from anorexia, being underweight, having an absence of ovulation, suffering from a pituitary or hypothalamus disorder, etc.

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

Elevated levels

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

1. 1. In women

In women, elevated FSH levels may indicate: menopausal or postmenopausal status (already mentioned), premature menopause, when undergoing hormone treatment, if you have polycystic ovary syndrome, if you have Turner's 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.

1.2. In males

In men, elevated FSH levels may indicate: castration, alcoholism, receiving chemotherapy, increased testosterone, Klinefelter's syndrome, taking testosterone-containing drugs, andropause, etc.

2. Low levels

On the other hand, low levels of the hormone, in women indicate malfunctioning of the ovaries to produce eggs, pregnancy, anorexia nervosa, treatment with Birth Control pills, etc.being under treatment with contraceptive pills or corticosteroids, etc.

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

The follicle-stimulating hormone test

It is very common, especially among women, to have a follicle stimulating hormone test. This test measures the amount of this hormone in a blood sample.

It is mainly used to evaluate the ovarian function.This involves the evaluation of the degree of fertility in women. Typically, the follicle-stimulating hormone test is performed in assisted reproduction centers (although not only in these), where women who show difficulties (together with their partner, or not) to get pregnant come.

What is the FSH test used for?

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

Specifically, the FSH test allows us to determine whether the male or female sex organs (ovaries or testes) are functioning properly, or if there is an underlying problem that is making it difficult to become pregnant. On the other hand, the test also allows confirming if the woman is in the menopausal stage.

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

• Precocious or delayed puberty
• Causes of 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, population reference values are consulted, depending on the age and gender of the person in of the person in question. The phase of the menstrual cycle in which she is in is also taken into account.

Bibliographic references:

• Carlson, N.R. (2005). Behavioral physiology. Madrid: Pearson Educación.
• Prieto-Gómez, 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.