ExitCare ImageMenstruation is the monthly passing of blood, tissue, fluid and mucus, also know as a period. Your body is shedding the lining of the uterus. The flow, or amount of blood, usually lasts from 3 to 7 days each month. Hormones control the menstrual cycle. Hormones are a chemical substance produced by endocrine glands in the body to regulate different bodily functions.

The first menstrual period may start any time between age 8 to 16 years. However, it usually starts around age 11 or 12. Some girls have regular monthly menstrual cycles right from the beginning. However, it is not unusual to have only a couple of drops of blood or spotting when you first start menstruating. It is also not unusual to have two periods a month or miss a month or two when first starting your periods.


Symptoms that may occur 5 to 10 days before your menstrual period starts, which is referred to as premenstrual syndrome (PMS). These symptoms can include:

These are normal signs and symptoms and can vary in severity. To help relieve these problems, ask your caregiver if you can take over-the-counter medications for pain or discomfort. If the symptoms are not controllable, see your caregiver for help.


Menstruation comes about because of hormones produced by the pituitary gland in the brain and the ovaries that affect the uterine lining.

First, the pituitary gland in the brain produces the hormone Follicle Stimulating Hormone (FSH). FSH stimulates the ovaries to produce estrogen, which thickens the uterine lining and begins to develop an egg in the ovary. About 14 days later, the pituitary gland produces another hormone called Luteinizing Hormone (LH). LH causes the egg to come out of a sac in the ovary (ovulation). The empty sac on the ovary called the corpus luteum is stimulated by another hormone from the pituitary gland called luteotropin. The corpus luteum begins to produce the estrogen and progesterone hormone. The progesterone hormone prepares the lining of the uterus to have the fertilized egg (egg and sperm) attach to the lining of the uterus and begin to develop into a fetus. If the egg is not fertilized, the corpus luteum stops producing estrogen and progesterone, it disappears, the lining of the uterus sloughs off and a menstrual period begins. Then the menstrual cycle starts all over again and will continue monthly unless pregnancy occurs or menopause begins.

The secretion of hormones is complex. Various parts of the body become involved in many chemical activities. Female sex hormones have other functions in a woman's body as well. Estrogen increases a woman's sex drive (libido). It naturally helps body get rid of fluids (diuretic). It also aids in the process of building new bone. Therefore, maintaining hormonal health is essential to all levels of a woman's well being. These hormones are usually present in normal amounts and cause you to menstruate. It is the relationship between the (small) levels of the hormones that is critical. When the balance is upset, menstrual irregularities can occur.