Severe acute bleeding, such as caused by ectopic pregnancy and post-partum hemorrhage, leads to hypovolemia (the depletion of blood from the circulation), progressing to shock. This is a medical emergency and requires hospital attendance and intravenous fluids, usually followed by blood transfusion. Once the circulating volume has been restored, investigations are performed to identify the source of bleeding and address it. Uncontrolled life-threatening bleeding may require uterine artery embolization (occlusion of the blood vessels supplying the uterus), laparotomy (surgical opening of the abdomen), occasionally leading to hysterectomy (removal of the uterus) as a last resort.

A possible complication from protracted vaginal blood loss is iron deficiency anemia, which can develop insidiously. Eliminating the cause will resolve the anemia, although some women require iron supplements or blood transfusions to improve the anemia.

Drug of choice is progesterone.

Management of dysfunctional uterine bleeding predominantly consists of reassurance, though mid-cycle estrogen and late-cycle progestin can be used for mid- and late-cycle bleeding respectively.

Also, non-specific hormonal therapy such as combined high-dose estrogen and high-dose progestin can be given. Ormeloxifene is a non-hormonal medication that treats DUB but is only legally available in India.

The goal of therapy should be to arrest bleeding, replace lost iron to avoid anemia, and prevent future bleeding.

Excessive movement before any treatments or surgeries will cause excessive bleeding.

A hysterectomy may be performed in some cases.

In postmenopausal bleeding, guidelines from the United States consider transvaginal ultrasonography to be an appropriate first-line procedure to identify which women are at higher risk of endometrial cancer. A cut-off threshold of 3 mm or less of endometrial thickness should be used for in women with postmenopausal bleeding in the following cases:

- Not having used hormone replacement therapy for a year or more

- Usage of continuous hormone replacement therapy consisting of both an estrogen and a progestagen

A cut-off threshold of 5 mm or less should be used for women on sequential hormone replacement therapy consisting both of an estrogen and a progestagen.

It the endometrial thickness equals the cut-off threshold or is thinner, and the ultrasonography is otherwise reassuring, no further action need be taken. Further investigations should be carried out if symptoms recur.

If the ultrasonography is not reassuring, hysteroscopy and endometrial biopsy should be performed. The biopsy may be obtained either by curettage at the same time as inpatient or outpatient hysteroscopy, or by using an endometrium sampling device such as a pipelle which can practically be done directly after the ultrasonography.

Treatment depends on the cause. In cases where malignancy is ruled out, hormone supplementation or the therapeutic use of hormonal contraception is usually recommended to induce bleeding on a regular schedule. Selective progesterone receptor modulators (SPRMs) are sometimes used to stop uterine bleeding.

Breakthrough bleeding that does not resolve on its own is a common reason for women to switch to different pill formulations, or to switch to a non-hormonal method of birth control.

Breakthrough bleeding is most commonly caused by an excessively thick endometrium (uterine lining). This is not a dangerous condition, though the unpredictable and often lengthy periods of bleeding are unpleasant. Breakthrough bleeding may also be caused by hormonal effects of ovulation. Breakthrough bleeding may also itself be a symptom of pregnancy.

Breakthrough bleeding is most common when a woman first begins taking oral contraceptives, or changes from one particular oral contraceptive to another, though it is possible for breakthrough bleeding to happen at any time. Smokers are especially prone to breakthrough bleeding while taking oral contraceptives; though many users experience breakthrough bleeding in the first three cycles of taking the pill, non-smokers tend to see the bleeding dissipate more quickly than smokers.

Breakthrough bleeding is likely due to hormonal fluctuations. The body is programmed to make certain estrogen levels each day and the estrogen (and some additional hormones, such as FSH, LH, and Progesterone) are responsible for regulating endometrium shedding. Therefore, when new levels of hormones enter the body through oral contraceptives, the body is provided with two ways to receive estrogen. These excess estrogen levels can cause pre-period bleeding (bleeding through). This should be regulated in several months.

According to "Lange Gynecology and Obstetrics", 8th edition, the most common side effect associated with OC use is breakthrough bleeding. It usually occurs during the first one or two cycles and resolves itself spontaneously. Another common problem is amenorrhea. Persistent break through bleeding and amenorrhea commonly reflect an atrophic, or thin and poorly developed, endometrium.

Use of combined estrogen and progesterone eliminates the normal endogenous hormonal cycling and gradually produces atrophy of the endometrial glands. This is because the dosage of estrogen in the OCs pills is much lower than the quantity produced naturally by the ovaries. Higher quantities produced by the ovaries induce proliferation, but low levels supplied by the pills produce atrophy but are sufficient to inhibit the endogenous secretion of the gonadotropins.

The exact chain of events that lead from an atrophic endometrium to the spotting between menses is not explained by the text. This condition may be corrected by using a pill with a higher estrogen (which will stimulate further proliferation of the endometrium) or lower progestin content (which will reduce its stability).

Menometrorrhagia is a condition in which prolonged or excessive uterine bleeding occurs irregularly and more frequently than normal. It is thus a combination of metrorrhagia and menorrhagia.

Dysfunctional uterine bleeding (DUB) is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable structural or organic disease. It is usually due to hormonal disturbances: reduced levels of progesterone cause low levels of prostaglandin F2alpha and cause menorrhagia (abnormally heavy flow); increased levels of tissue plasminogen activator (TPA) (a fibrinolytic enzyme) lead to more fibrinolysis.

Diagnosis must be made by exclusion, since organic pathology must first be ruled out.

DUB can be classified as "ovulatory" or "anovulatory", depending on whether ovulation is occurring or not. It is usually a menstrual disorder, although abnormal bleeding from the uterus is possible outside menstruation.

Some sources state that the term "dysfunctional" implies a hormonal mechanism. Use of the term "abnormal uterine bleeding" is preferred in today's medicine.

Dysmenorrhea (or dysmenorrhoea), cramps or painful menstruation, involves menstrual periods that are accompanied by either sharp, intermittent pain or dull, aching pain, usually in the pelvis or lower abdomen.

A menstrual disorder is an abnormal condition in a woman's menstrual cycle.

Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia (vaginal bleeding between expected periods).

Irregular cycles or irregular periods is an abnormal variation in length of menstrual cycles. A female usually experiences cycle length variations of up to eight days between the shortest and longest cycle lengths. Lengths ranging between eight and 20 days are considered moderately irregular. Variation of 21 days or more is considered very irregular.

Alternatively, a single menstruation period may be defined as irregular if it is shorter than 21 days or longer than 36 days. If they are regularly shorter than 21 days or longer than 36 (or 35) days, the condition is termed polymenorrhea or oligomenorrhea, respectively.