Every month, a woman’s body goes through four phases or stages in her menstrual cycle. The body transitions from one phase to the next due to hormonal changes. The four phases of the menstrual cycle are as follows:
- Menstrual phase
- Follicular phase
- Ovulation phase
- Luteal phase
The phase duration differs from woman to woman due to hormonal changes. The length of the phases may also vary with age.
Here’s everything you need to know about the menstrual cycle, starting with the first phase.
- The menstrual phase
The menstrual phase is the time when you get your period. This phase begins when the egg from the previous cycle is not fertilised due to a missed pregnancy. The thicker uterine linings shed through the vagina, resulting in the period, as the linings are no longer required to support the expected pregnancy.
The menstrual period lasts 3 to 7 days on average. Typically, heavy flow occurs during the first 2-3 days of the period and ceases by the seventh day.
You may experience the following menstrual problems during and even before your period:
- Abdominal and low back cramps or pain
- Mood swings
- Breast pain
- Acne breakouts
- The follicular phase
The follicular phase, also known as the proliferative phase, starts on the first day of the period and ends with ovulation. The follicular phase lasts about 10-16 days on average.
In this phase, the body releases Follicle-Stimulating Hormone (FSH), which triggers the ovaries to produce several small sacs containing immature eggs called follicles.
The healthiest egg develops in the sac, and the rest is absorbed by the body. As the egg matures, the body produces more oestrogen to thicken the uterine lining and deliver nutrients to the fertilised egg.
- The ovulation phase
The ovulation phase begins when rising oestrogen levels cause the release of the luteinizing hormone (LH). The ovary releases a mature egg during the ovulation phase.
Ovulation usually begins around the 14th day of a 28-day menstrual cycle. The mature egg travels to the uterus via the fallopian tube to be fertilised by sperm. If the egg is not fertilised within 24 hours, it dissolves.
- The luteal phase
When a fertilised egg lands in the uterine lining after ovulation, the ovary cells, known as the corpus luteum, release progesterone along with a small amount of oestrogen to thicken the lines to prepare for incubation.
When pregnancy does not occur, progesterone levels fall, and the uterine lining sheds, resulting in the onset of menstruation. The phase can last up to 14 days on average.
The menstrual cycle duration varies from woman to woman, depending on physiological functions, medical conditions, and other lifestyle factors. Some women may experience heavy bleeding, longer periods, and severe pain, while others have shorter periods, less bleeding, and no or minor period pain.
If you are concerned or want to learn more about your menstrual cycle, speak with your doctor.