Phases of the Menstrual Cycle

The menstrual cycle is divided into several distinct phases, each characterized by specific hormonal changes and physiological events. While the average menstrual cycle lasts around 28 days, it can vary in length from woman to woman. Here are the key phases of the menstrual cycle:

Menstruation (Day 1-5):

The menstrual cycle begins with menstruation, also known as the period. This phase marks the shedding of the uterine lining (endometrium) that had built up in the previous cycle.
Menstruation typically lasts 3 to 7 days, though it can vary.

Follicular Phase (Day 1-13):

This phase coincides with menstruation and extends until ovulation.
The brain’s pituitary gland releases follicle-stimulating hormone (FSH), which stimulates the ovaries to produce several small sacs called follicles.
One of these follicles will become dominant and continue to develop, while the others degenerate.
The dominant follicle releases increasing amounts of estrogen, which helps thicken the uterine lining.

Ovulation (Day 14):

Ovulation is the release of a mature egg (ovum) from the dominant follicle in one of the ovaries.
It is triggered by a surge in luteinizing hormone (LH) and is typically around the midpoint of the menstrual cycle.
The egg is released into the fallopian tube, where it may be fertilized by sperm if sexual intercourse occurs.

Luteal Phase (Day 15-28):

Following ovulation, the ruptured follicle transforms into a temporary endocrine structure called the corpus luteum.
The corpus luteum secretes both progesterone and some estrogen.
Progesterone maintains the thickened uterine lining in preparation for the potential implantation of a fertilized egg.
If fertilization and implantation do not occur, the corpus luteum degenerates, leading to a drop in progesterone and estrogen levels.

Pre-Menstrual Phase (Day 21-28):

In the absence of pregnancy, the declining levels of progesterone and estrogen in the luteal phase signal the body to prepare for menstruation.
Some women may experience premenstrual symptoms during this phase, including mood changes, breast tenderness, and bloating.
If pregnancy occurs, this phase transitions into early pregnancy with the development of the placenta.
The menstrual cycle then repeats, with menstruation marking the beginning of a new cycle. It’s important to note that variations in cycle length and hormonal patterns are common and can be influenced by factors like stress, illness, weight changes, and underlying medical conditions.

Tracking your menstrual cycle can be helpful for understanding your fertility, planning contraception, and identifying potential health issues. If you have concerns about your menstrual cycle or experience irregularities or severe symptoms, it’s advisable to consult a healthcare provider for evaluation and guidance.