Normal menstrual flow lasts approximately five days and occurs every 21 to 35 days. Abnormal uterine bleeding is when you bleed between your monthly periods, or when you bleed for too long or it is an extremely heavy flow.

What causes abnormal uterine bleeding?
There are many causes of abnormal uterine bleeding. One major cause is due to structural abnormalities in the uterus. This can take the form of fibroids, which are benign overgrowth of the muscle of the uterus. This can also take the form of polyps, which are benign overgrowths of the lining of the uterus or on the cervix. Uterine cancer or cervical cancer is an important cause as well.
There are also non-structural causes of abnormal uterine bleeding. Bleeding disorders or platelet dysfunction can cause abnormal bleeding. Early pregnancies can have some bleeding associated with them. Hormonal changes can also be a cause.
Polycystic ovary syndrome (PCOS, cysts in the ovaries) may cause your periods to come at different times or not at all. It is caused when certain hormones are out of balance. When this happens, you may have difficulty getting pregnant. You may grow hair on your body and face. Also, the hair on your scalp may get thinner.
Women who are going into menopause or are in menopause are more apt to have changes in hormones. The changes can cause the lining of the uterus (endometrium) to get thick. This can cause bleeding.
For women who are in menopause, any bleeding should be thought of as not normal and should be investigated.

How will abnormal bleeding be assessed?
The work-up will start with a history. Your doctor will ask you what brings on the bleeding. He or she will ask about any other symptoms you might be having and whether you might be pregnant. After that, there will be a physical exam. This will include a pelvic exam, exam of the cervix, and possibly a Pap smear.
If you are not in menopause, a test to see if you are going to have a baby may be done. Blood tests to check how your blood clots and a complete blood count may be done. The doctor may also test your thyroid. Problems with thyroid function may be a sign that there is also a problem with ovary function. Hormone levels may be checked.
A hysteroscopic exam of the endometrium may be done to look for fibroids, polyps, or signs of cancer. A pelvic ultrasound may also help to find these problems. If you have risk factors for cancer in this area, a biopsy of the endometrium may be done.

How will it be treated?

Hormones are often used to treat this condition. Birth control pills can control your periods. They can also slow the growth of the endometrium. Progestin alone can prevent very heavy bleeding in women who do not ovulate the same each month. Progestin can also be given by a shot, implant, or device put into your uterus (intrauterine device [IUD]).
A nonsteroidal anti-inflammatory drug such as ibuprofen may also reduce blood loss if you bleed a lot during your period. It can also help with the pain of cramps during your period.
You might need surgery to get rid of uterine fibroids and polyps. One option for getting rid of fibroids is called uterine artery embolization. With this, the fibroids’ blood supply is cut off by putting tiny particles into the uterine arteries. This makes the fibroids shrink. Uterine fibroids can also be removed surgically, while keeping the uterus and the ability to have children. This is called a myomectomy.
Surgery to destroy the lining of the uterus, called uterine ablation, may be an option for some women. With this, the lining of the uterus is destroyed through the use of a laser, heat, electricity, microwave energy, or freezing.
Taking out the uterus (hysterectomy) may be tried as a last resort. This may be done when hormone treatment fails to control heavy bleeding.
Cancer or cancerous changes in the endometrium are often treated with hysterectomy. This is sometimes followed by radiation. If cervical cancer is the cause, the treatment depends on the stage of the cancer. Hysterectomy is often used to treat early stages. More advanced stages may need radiation or chemotherapy.
Whatever the problem is, it is important to understand that there are many treatment options available. You do not have to suffer.