Menstrual cycle — Definition & Meaning

The roughly monthly hormonal cycle that prepares the body for a possible pregnancy.

The menstrual cycle is the recurring sequence of hormonal changes that prepares the ovary and uterus for a possible pregnancy. It is commonly divided into the follicular phase, ovulation, and the luteal phase.

Cycle length and regularity vary between people and change across the reproductive years, becoming irregular during perimenopause.

Related terms

Follicular phase

The first half of the menstrual cycle, when a follicle matures and estrogen rises.

Ovulation

The release of a mature egg from the ovary, usually around the middle of the menstrual cycle.

Luteal phase

The second half of the menstrual cycle, after ovulation, when progesterone rises.

Amenorrhea

The absence of menstrual periods, either never starting or stopping for several months.

Perimenopause

The transitional years before menopause when cycles become irregular and symptoms often begin.

Source

Office on Women’s Health: Your Menstrual Cycle

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