How to calculate 28 days of menstruation

In fact, many people do not have a clear understanding of their menstrual cycle, which will lead to many situations. If your menstrual cycle is 28 days, there is no problem. This does not fall into the category of menstrual abnormalities. Generally speaking, if the time is shorter, it is considered irregular menstruation. However, the most important thing is to learn to self-regulate so that you can be healthier.

The female internal reproductive organs consist of the ovaries, uterus, and fallopian tubes. The main function of the ovaries is to produce eggs and synthesize ovarian hormones, while the uterus and fallopian tubes are reproductive organs. The ovaries contain hundreds of thousands of follicles, each of which contains one egg.

Before puberty, the follicles are essentially non-functional. During puberty, under the action of gonadotropin from the anterior pituitary gland, immature follicles gradually develop and synthesize estrogen. When the follicle matures and ovulates, the follicle wall collapses, the cells become larger and yellower, and are called the corpus luteum. It synthesizes estrogen and produces progesterone.

As the ovaries change, the endometrium is also affected and undergoes corresponding cyclical changes. Estrogen causes the endometrium to thicken, the endometrial cells to increase in number and size, and the arterioles in the interstitium to become more tortuous and spiral, which is called the proliferative endometrium. After ovulation, due to the combined effects of estrogen and progesterone, the endometrium becomes edematous, the glands produce a large amount of mucus and glycogen, and the thickness of the endometrium increases from 1 mm to 6 mm, which is called the secretory endometrium.

If the egg released at this time is fertilized, the fertilized egg is transported to the uterus through the fallopian tube for development, which is called pregnancy. The pregnancy tissue synthesizes a chorionic gonadotropin, which supports the continued development of the corpus luteum of the ovary. If the egg is not fertilized, the corpus luteum will atrophy and stop secreting estrogen and progesterone about 14 days after ovulation. At this time, the blood vessels in the endometrium will contract, the endometrium will necrotize and fall off, causing bleeding and forming menstruation.

Therefore, the length of the menstrual cycle depends on the length of the ovarian cycle, which is generally 21-30 days, but varies from person to person, and may be 23-45 days, or even 3 months or half a year as a cycle. As long as it is regular, it is generally considered normal menstruation.

The bleeding time is generally 3-7 days, and the total amount of bleeding each time is 30-50ml. Some people believe that menstrual volume exceeding 80ml is a pathological condition.

② As the follicles mature, the secretion of estrogen also increases gradually. When it reaches a certain concentration, it promotes the anterior pituitary to increase the secretion of gonadotropin through positive feedback to the hypothalamus and pituitary, and the increase in LH secretion is more obvious, forming a peak of luteinizing hormone release, which causes the mature follicle to ovulate;

③ Under the action of luteinizing hormone, the ovulatory follicle forms a corpus luteum and secretes estrogen and progesterone. During this period, the endometrium, mainly under the action of progesterone, accelerates growth and functional differentiation, transforming into secretory endometrium;

④ As the corpus luteum secretes a large amount of estrogen and progesterone, the concentrations of these two hormones in the blood increase, which inhibit the hypothalamus and pituitary gland through negative feedback, causing the pituitary gland to secrete less follicle-stimulating hormone and luteinizing hormone. The corpus luteum then atrophies, and as a result, the progesterone and estrogen also decrease rapidly. The endometrium suddenly loses the support of these two sex hormones, collapses and bleeds, and the endometrium falls off, resulting in menstruation.