What Causes a Shortened Menstrual Cycle?

The reasons for shortened female menstrual cycle are complex, with common ones including age, ovulation bleeding, and luteal insufficiency. Generally speaking, occasional shortened menstrual cycle is not a big issue. However, if this occurs for a long period, it may affect ovulation, even leading to anovulation and subsequent infertility. Therefore, it should be taken seriously.

1. Age: Age is one of the major reasons for shortened menstrual cycle. In general, women experience shortened menstrual cycles during puberty and menopause.

2. Insufficient ovarian reserve: Women's ovarian reserve capacity begins to decline after 35 years old. The menstrual cycle is regulated by the interaction between the three hormones - hypothalamus, pituitary, and ovaries. With a decline in ovarian reserve, menstruation is more likely to occur.

3. Luteal insufficiency: Menstruation occurs when the corpus luteum shrinks, leading to a decrease in estrogen and progesterone secretion. As the endometrium fails to receive hormonal support, it undergoes necrosis and shedding. Luteal insufficiency shortens the entire luteal phase, resulting in more frequent menstruation.

4. Ovulation bleeding: Although ovulation bleeding may appear similar to menstruation, it is essentially bleeding caused by ovulation, not menstruation due to endometrial shedding. Some people may mistake ovulation bleeding for menstruation, thus believing that the menstrual cycle is shorter.