Dysfunctional Uterine Bleeding: Causes, Prevention & Treatment

Dysfunctional Uterine Bleeding

Dysfunctional Uterine Bleeding (DUB) is abnormal uterine bleeding. DUB is a condition that causes vaginal bleeding to occur outside of the regular menstrual cycle. Girls experiencing puberty and women entering menopause can have imbalanced hormone levels for months or even years. Dysfunctional uterine

bleeding commonly results when the level of estrogen remains high instead of decreasing as it normally does after an egg is released and is not fertilized. The high estrogen level is not balanced by an appropriate level of progesterone. In such cases, no egg is released, and the lining of the uterus may continue to thicken instead of breaking down and being shed normally as a menstrual period. This abnormal thickening is called endometrial hyperplasia. Periodically, the thickened lining is shed incompletely and irregularly, causing bleeding. Bleeding is irregular, prolonged, and sometimes heavy. This type of bleeding is common among women who have polycystic ovary syndrome and occurs in some women with endometriosis. If this cycle of abnormal thickening and irregular shedding continues, precancerous cells may develop, increasing the risk of cancer of the uterine lining (endometrial cancer), even in young women. Dysfunctional uterine bleeding is often an early sign of menopause.


Medical conditions that often cause dysfunctional uterine bleeding are:

  • Polycystic Ovary Syndrome (PCOS). This is an endocrine disorder that causes a woman to produce an increased amount of sex hormones. This may lead to an imbalance in estrogen and progesterone, making the menstrual cycle irregular.  
  • Endometriosis. This condition results when the uterine lining grows outside of the uterus, often on the ovaries. Endometriosis often causes heavy bleeding during regular periods. 
  • Uterine Polyps. These small growths occur within the uterus. Although their cause is unknown, polyp growth is heavily influenced by the hormone estrogen. Small blood vessels in the polyps can cause DUB. 
  • Uterine Fibroids. Uterine fibroids are small growths that occur within the uterus, uterine lining or uterine muscle. Like polyps, the causes of uterine fibroids are unknown. But estrogen seems to play a role in their growth. 
  • Sexually Transmitted Diseases (STDs). STDs that cause lesions, like gonorrhea and chlamydia, may lead to DUB. Bleeding caused by STDs usually occurs after sex, when the lesions are aggravated.  


You may have dysfunctional uterine bleeding if you have one or more of the following symptoms:

  • You get your period more often than every 21 days or farther apart than 35 days. A normal adult menstrual cycle is 21 to 35 days long. A normal teen cycle is 21 to 45 days.
  • Your period lasts longer than 7 days (normally 4 to 6 days).
  • Your bleeding is heavier than normal. If you are passing blood clots and soaking through your usual pads or tampons each hour for 2 or more hours, your bleeding is considered severe and you should call your doctor.

If you experience any of the following severe DUB symptoms, contact your doctor immediately:

  • dizziness
  • fainting
  • weakness
  • low blood pressure
  • increased heart rate
  • pale skin
  • pain
  • passing large clots
  • soaking a pad every hour

Your doctor will ask about your medical history and about symptoms that might suggest a cause for the irregular bleeding or other hormonal abnormalities. The doctor may do various tests to check for these causes of abnormal bleeding patterns:

  • Pregnancy – Urine or blood tests
  • Thyroid hormone and prolactin hormone abnormalities – Blood tests
  • Menopause (especially in women in their 40s or 50s) – Blood tests to determine if estrogen levels are falling, which suggests the beginning stages of menopause
  • Abnormalities of the uterus or ovaries – A transvaginal ultrasound in which a small, rodlike probe is inserted into the vagina to take measurements of the endometrial lining
  • Possible cancer in women over 35; or those who have had breast, ovarian or colon cancer; or who have a strong family history of these cancers; or who have not had a period in six months – An endometrial biopsy, done in the office, in which the doctor uses a speculum to look at the cervix, then inserts a thin, straw-like tube through the cervix into the uterus, and brushes it along the endometrial layer to collect a tissue sample

If you have heavy bleeding, your doctor will check iron levels in your blood to see if you are anemic.


Treatment depends on how old the woman is, how heavy the bleeding is, whether the uterine lining is thickened, and whether the woman wishes to become pregnant. It focuses on controlling the bleeding and, if needed, preventing endometrial cancer. Bleeding can be controlled using drugs, which may be hormones or not. Drugs that are not hormones are often used first, especially in younger women, because they have fewer side effects.

  • Hormones, such as a progestin pill or daily birth control pill (progestin and estrogen). These hormones help control the menstrual cycle and reduce bleeding and cramping.
  • A short course of high-dose estrogen. Estrogen is a hormone that is often used to stop dangerously heavy bleeding.
  • Use of the levonorgestrel IUD, which releases a progesterone-like hormone into the uterus. This reduces bleeding while preventing pregnancy.
  • Rarely used medicines that stop estrogen production and menstruation, such as gonadotropin-releasing hormones. These drugs can cause severe side effects but are used in special cases.
  • Surgery, such as endometrial ablation or hysterectomy, when other treatments do not work.

If you also have menstrual pain or heavy bleeding, you can take regular doses of a nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen. 

In some cases, doctors use watchful waiting, or a wait-and-see approach. It may be okay for a teen or for a woman nearing menopause. Some teens have times of irregular vaginal bleeding. This usually gets better over time as hormone levels even out. Women in menopause can expect their periods to stop. They may choose to wait and see if this happens before they try other treatments.


There is no way to prevent dysfunctional uterine bleeding. See a doctor promptly if you continue to have irregular periods. Early diagnosis and treatment can help to make your periods regular again, which is important for your overall health.