What Is a Normal Menstrual Cycle?

The menstrual cycle refers to the natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. The cycle is divided into four phases :

1. The follicular phase begins on the first day of menstruation and ends when ovulation occurs around day 14 of a 28-day cycle. During this phase, the levels of the hormone estrogen rise, causing the lining of the uterus to thicken in preparation for the implantation of a fertilized egg.

2. Ovulation occurs when a mature egg is released from one of the ovaries, usually around day 14 of a 28-day cycle. This process is triggered by a surge in the hormone luteinizing hormone (LH).

3. The luteal phase begins after ovulation and lasts until the menstrual period begins. During this phase, the corpus luteum, which is the remains of the ovarian follicle that released the egg, produces the hormone progesterone. Progesterone helps maintain the thickened uterine lining and prepares it for the implantation of a fertilized egg.

4. Menstruation begins when the fertilized egg does not implant in the uterus. The levels of estrogen and progesterone drop, causing the uterine lining to shed. This process is accompanied by bleeding, cramping, and other physical and emotional symptoms. The length of the menstrual cycle varies from woman to woman, but 28 days is considered average.

It's important to note that the menstrual cycle can be affected by factors like stress, diet, exercise, and certain medical conditions. If you experience any significant changes in your menstrual cycle, it's advisable to consult with a healthcare professional.