Why is this happening

Women are more than men affected by hormones. The increase of the uterus is influenced by three – progesterone, estrogen and serotonin.

Progesterone levels before menstruation increases dramatically. Thanks to this hormone in the body begins to stay liquid, a large part of the nutrients accumulates in the uterus. It is, accordingly, began to increase its inner layer becomes thicker, soft and loose. In addition, progesterone increases the production of sebum. Due to the delay of water in the body (especially the abdomen), the uterus is delayed more blood.

Progesterone – in women it prepares the inner layer of the uterus to retain the fertilized egg and helps child bearing.

The level of serotonin and estrogen before menstruation drops, which causes increased appetite and cravings for sweets and starchy foods. It also affects the increase of the uterus. Especially in combination with increased levels of progesterone.

Serotonin is a hormone involved in the regulation of the functions of the Central nervous system and the digestive, excretory and endocrine systems.

What does it do

The first half of the menstrual cycle (the first day of menstruation approximately 14 days) the uterus is restored after menstruation and at the same time, there is the maturation of the dominant follicle. Approximately day 14 of the cycle is determined by the dominant follicle and the uterus begins to prepare for a possible pregnancy.

In order to be ready to "take" a fertilized egg, its inner layer should be thick and loose. Then the egg can implant in the uterine wall and fixed there. After that the body gets the signal about the pregnancy, and the egg continues to develop in the uterus. As well as nutrients originated from embryo initially virtually no, he gets right out of the uterus. To do this, it must be filled with nutrients and "feed" the embryo until, until you grow up fully placenta. Thus, the increase of the uterus is necessary for two things – fixing and nutrition of a fertilized egg, and consequently to maintain a possible pregnancy.

If pregnancy does not occur, the uterus gets rid of "unnecessary burden" by menstruation.

Other causes of increased uterine

Other reasons for the increase of the uterus can be:

1. A possible pregnancy. The reasons for its increase are the same as before menstruation.
2. Various diseases – fibroids, adenomyosis and other.

It should be noted that among nulliparous women the uterus is always larger than in nulliparous.