Many women have emotional or physical changes during their monthly menstrual cycle. A woman can be depressed, moody or sad. This is PMs or premenstrual syndrome. At that time also, a woman's body tissues may become filled with water. So the body swells, making her feel fat. This happens because hormones affect the way the body uses salt, water stays in the body to balance the salt. Some women have a problem with the level of estrogen, one of the female hormones which controls women's features such as voice tone or enlarged breasts. In this case the woman's period is irregular and she may suffer severe PMS.