Possible reasons for a late period that is not due to pregnancy

What we call “period or menstruation” is the more or less cyclical bleeding (25-35 days) that occurs due to the complex action of multiple hormones and represents the end of the menstrual cycle to make way for the beginning of the next. All organs involved must function properly for it to happen.

I will create a brief timeline to review the possible causes that can interrupt or alter the function of these organs and, therefore, affect the rhythm of the menstruation.

The order to start comes from an area of ??the brain called the hypothalamus that produces hormones that act in certain cells of the pituitary (a small gland located in the brain) stimulating the production of gonadotropins (FSH and LH). These, in turn, will send the order for the subsequent production of the ovarian hormones: first estradiol and, later, progesterone. This will allow the normal sequence: growth of an ovarian follicle (which we call “dominant follicle“), rupture of said follicle with expulsion of the egg (oocyte), producing at that time ovulation and formation of the corpus luteum (remains of the broken follicle that has ovulated). The production of all these hormones acts at the same time in the endometrium (mucous membrane that lines the inside of the uterus), which will thicken throughout the cycle. If, finally, the egg is not fertilized by a sperm or, if it is, but the generated embryo is not capable of implanting and generating a pregnancy, the production of the ovarian hormones will drop and the endometrium will come off, causing menstrual bleeding.

Reasons for a late period

Therefore, there are multiple factors that can delay or make the period disappear if there are any alterations in the production of any of these hormones or the function of the glands that produce them.

At the level of the hypothalamus and / or the pituitary:

• Eating disorders that produce severe changes in body weight: extreme thinness caused by anorexia nervosa and, on the other extreme, overweight and, above all, obesity.
• Mood disorders: stress and anxiety
• Intense physical exercise (elite athletes)
• Organic processes such as tumors, infections or vascular lesions.

In the ovary:

• Age: beginning of the period during puberty and the period before menopause (pre/perimenopause)
• Women with Polycystic Ovary Syndrome (PCOS)
• Young women with premature primary ovarian failure (without apparent cause) or secondary to chromosomal alteration (eg Turner syndrome), after using oncological therapies (chemotherapy / radiotherapy), previous ovarian surgery,…
• Some types of ovarian tumors.

Chronic use of medications such as antidepressants, antipsychotics, corticosteroids, chemotherapy or the use of certain drugs.

Chronic diseases:

• Affecting the liver or kidney
• Endocrine disorders such as diabetes, alterations of thyroid function or excess production of prolactin (PRL) or issues of the adrenal glands.
• Digestive system disorders such as ulcerative colitis, Crohn’s disease, celiac disease…
• Viral infections such as AIDS (Acquired Immunodeficiency Syndrome)

All of these are examples of situations that can lead to a delay in the appearance of a period, including, in some cases, their disappearance (amenorrhea) temporarily or permanently.

If you have any questions about the behavior of your menstrual cycle, you should consult your gynecologist who will carry out the pertinent studies.

Just to add that the first cause of menstrual delay is pregnancy.

Dr. Lydia Luque, gynaecologist at Instituto Bernabeu