How much blood flow is considered normal? Doctors consider about 30 to 80 milliliters (2 tablespoons to about 1/3 cup) normal; anything less or more than that could be considered abnormal menstrual bleeding.
Irregular menstruation and abnormal menstrual bleeding fall into several different categories.
Amenorrhea is the failure to start menstruation during puberty or cessation of menstruation. Some of the normal causes of amenorrhea are pregnancy, lactation and menopause.
Dysmenorrhea is the medical term for menstrual cramps. "Primary dysmenorrhea" is not caused by an underlying medical condition and generally begins when a girl first starts having her period. "Secondary dysmenorrhea" typically occurs later in life and is the result of a problem with the woman's reproductive system.
Menorrhagia is excessive, dysfunctional uterine bleeding that occurs as a normal part of a woman's menstrual cycle. Blood flow may be high in volume (over 80 milliliters—about 1/3 cup) and may last longer than a normal period (usually eight to ten days).
Premenstrual Disorders
Premenstrual syndrome, or PMS, is a group of physical and emotional symptoms that occur in the latter half of the menstrual cycle following ovulation. Symptoms, which can include backache, bloating, irritability and headache, are typically most intense during the seven days prior to the start of menses.
Premenstrual dysphoric disorder, or PMDD, is a more severe form of PMS that also includes a psychological component. For a PMDD diagnosis certain symptomatic criteria must be met and the symptoms must interfere with daily living.
