Abnormal vaginal bleeding includes any vaginal bleeding that occurs
Before puberty
Between menstrual periods
During pregnancy
After menopause (12 months or more after the last menstrual period)
During the childbearing years, vaginal bleeding occurs normally as menstrual periods. However, menstrual periods are considered abnormal if they
Become excessively heavy (saturating more than 1 or 2 tampons an hour)
Last too long (more than 7 days)
Occur too frequently (usually fewer than 21 days apart)
Occur too infrequently (usually more than 90 days apart)
Typically, menstrual periods last from 3 to 7 days and occur every 21 to 35 days. In adolescents, the interval between periods varies more and may be as long as 45 days.
Vaginal bleeding may occur during early pregnancy or during late pregnancy and may result from problems (complications) related to the pregnancy.
Prolonged or excessive bleeding, regardless of cause, can result in iron deficiency, anemia, and sometimes dangerously low blood pressure (shock).
Causes of Vaginal Bleeding
Vaginal bleeding may result from
Malfunction of the complex hormonal system that regulates the menstrual cycle
A disorder of the vagina, uterus, cervix, or another reproductive organ, such as fibroids, infection, or cancer
Disorders that cause excessive bleeding (uncommon)
Common causes
Likely causes of vaginal bleeding depend on the woman’s age.
Newborn girls may have a small amount of vaginal bleeding. Before birth, they absorb estrogen through the placenta from the mother. After birth, these high levels of estrogen decrease rapidly, sometimes causing a little bleeding during the first 1 to 2 weeks of life.
During childhood, vaginal bleeding is abnormal and uncommon. When it occurs, it is most often caused by
A foreign object (body), such as toilet paper or a toy, in the vagina
An injury, or possible sexual abuse
Infections in the vagina (vaginitis)
During the childbearing years, the most common cause is
Hormonal imbalance that causes ovulation to be delayed or not happen (ovulatory dysfunction), which can cause abnormal uterine bleeding
Uterine bleeding due to ovulatory dysfunction occurs when the hormonal control of menstruation changes and the lining of the uterus sheds irregularly. It is more likely to occur in adolescents (when menstrual periods are just starting) or in women in their late 40s (when periods are nearing an end).
Other common causes of vaginal bleeding during the childbearing years include
Complications of pregnancy (sometimes when a woman who does not know she is pregnant)
Fibroids (muscle masses) inside the uterus
Polyps in the cervix or uterus
Bleeding when the egg is released (at ovulation) during the menstrual cycle
Use of birth control pills (oral contraceptives), if there is spotting or bleeding between periods (called breakthrough bleeding)
After menopause, the most common cause is
Age-related thinning of the lining of the vagina (formerly called atrophic vaginitis) or uterus (part of the genitourinary syndrome of menopause)
Less common causes
Cervical cancer, vaginal cancer, or cancer of the lining of the uterus (endometrial cancer) can cause bleeding, usually after menopause. Cancer is not a common cause during the childbearing years.
Certain hormonal disorders (such as hypothyroidism) are a less common cause of bleeding.
Excessively heavy menstrual periods may be the first sign of a bleeding disorder.
Children may have hormonal abnormalities that cause puberty to begin too early—a disorder called precocious puberty. In these children, menstrual periods start, breasts develop, and pubic and underarm hair appears too soon.
Rarely, bleeding is caused by a tumor or an injury resulting from unsuspected child abuse.
