When is menses

What is menstruation? How does the menstrual cycle work? How can I figure out what is happening in my cycle? When am I ovulating? Menstruation is the technical term for getting your period. About once a month, females who have gone through puberty will experience menstrual bleeding.

This happens because the lining of the uterus has prepared itself for a possible pregnancy by becoming thicker and richer in blood vessels. If pregnancy does not occur, this thickened lining is shed, accompanied by bleeding. Bleeding usually lasts for days. For most women, menstruation happens in a fairly regular, predictable pattern. The length of time from the first day of one period to the first day of the next period normally ranges from days. The menstrual cycle is controlled by a complex orchestra of hormones, produced by two structures in the brain, the pituitary gland and the hypothalamus along with the ovaries.

If you just want a quick, general overview of the menstrual cycle, read this description. For a more detailed review of the physical and hormonal changes that happen over the menstrual cycle, click here. The menstrual cycle includes several phases. The exact timing of the phases of the cycle is a little bit different for every woman and can change over time.

Once the bleeding stops, the uterine lining also called the endometrium begins to prepare for the possibility of a pregnancy. Somewhere around day 14, an egg is released from one of the ovaries and begins its journey down the fallopian tubes to the uterus.

In this case the fertilized egg will travel to the uterus and attempt to implant in the uterine wall. If the egg was not fertilized or implantation does not occur, hormonal changes signal the uterus to prepare to shed its lining, and the egg breaks down and is shed along with lining. This phase of the menstrual cycle occurs from approximately day Day 1 is the first day of bright red bleeding, and the end of this phase is marked by ovulation. While menstrual bleeding does happen in the early part of this phase, the ovaries are simultaneously preparing to ovulate again.

The pituitary gland located at the base of the brain releases a hormone called FSH — follicle stimulating hormone. Eventually, one of these follicle becomes dominant and within it develops a single mature egg; the other follicles shrink back.

If more than one follicle reaches maturity, this can lead to twins or more. The maturing follicle produces the hormone estrogen, which increases over the follicular phase and peaks in the day or two prior to ovulation. The lining of the uterus endometrium becomes thicker and more enriched with blood in the second part of this phase after menstruation is over , in response to increasing levels of estrogen.

High levels of estrogen stimulate the production of gonadotropin-releasing hormone GnRH , which in turn stimulates the pituitary gland to secrete luteinizing hormone LH.

The surge in LH also causes a brief surge in testosterone, which increases sex drive, right at the most fertile time of the cycle. The release of the mature egg happens on about day 14 as a result of a surge in LH and FSH over the previous day.

After release, the egg enters the fallopian tube where fertilization may take place, if sperm are present. Contact a health care provider if you have questions about your health. Menstruation Also called: Menses, Menstrual period, Period. Learn More Related Issues Specifics. See, Play and Learn No links available. Research Clinical Trials Journal Articles. Resources Reference Desk Find an Expert. Besides bleeding from the vagina, you may have Abdominal or pelvic cramping pain Lower back pain Bloating and sore breasts Food cravings Mood swings and irritability Headache and fatigue Premenstrual syndrome , or PMS, is a group of symptoms that start before the period.

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Please try again. Something went wrong on our side, please try again. Show references Kaunitz A, et al. Approach to abnormal uterine bleeding in nonpregnant reproductive-age women.

Accessed March 22, Welt C, et al. Evaluation of the menstrual cycle and timing of ovulation. Barrett KE, et al. In: Ganong's Review of Medical Physiology.