Abnormal Uterine Bleeding (AUB)

Abnormal uterine bleeding (AUB) is a broad term for any bleeding from the uterus that differs from a normal menstrual cycle. This includes changes in the regularity, frequency, duration, or volume of your menstrual flow, or bleeding between periods. The American College of Obstetricians and Gynecologists (ACOG) defines AUB as bleeding from the uterus that is abnormal in volume, regularity, and/or timing, and has been present for the majority of the past 6 months. There are two main types of AUB: Acute AUB: An episode of heavy bleeding that requires immediate medical attention to prevent further blood loss. Chronic AUB: Abnormal bleeding from the uterus that has been present for most of the past 6 months. Older terms for abnormal bleeding are now discouraged in favor of simpler, more precise descriptions. For example, "menorrhagia" is now called Heavy Menstrual Bleeding (HMB), and "metrorrhagia" is now Intermenstrual Bleeding (IMB). "Dysfunctional Uterine Bleeding (DUB)" is an outdated term, replaced by a more specific classification system.

Symptoms

Heavy Menstrual Bleeding (HMB): Soaking through one or more sanitary pads or tampons every hour for several consecutive hours
Heavy Menstrual Bleeding (HMB): Needing to wake up to change sanitary protection during the night
Heavy Menstrual Bleeding (HMB): Menstrual flow with blood clots the size of a quarter or larger
Heavy Menstrual Bleeding (HMB): Bleeding for longer than 7-8 days
Heavy Menstrual Bleeding (HMB): Symptoms of anemia, such as tiredness, fatigue, or shortness of breath
Intermenstrual Bleeding (IMB): Bleeding between periods
Irregular Bleeding: Unpredictable timing and volume of bleeding
Postcoital Bleeding: Bleeding after sexual intercourse
Pelvic pain or pressure
Emergency Symptom: Severe, profuse vaginal bleeding soaking more than one pad per hour
Emergency Symptom: Dizziness, lightheadedness, or fainting (syncope)
Emergency Symptom: Tachycardia (rapid heart rate)
Emergency Symptom: Hypotension (low blood pressure)
Emergency Symptom: Pallor (unusual paleness) and shortness of breath
Red Flag Symptom: Any bleeding after menopause
Red Flag Symptom: AUB in women with risk factors for endometrial cancer (e.g., obesity, PCOS, tamoxifen use, family history of certain cancers)
Red Flag Symptom: Persistent intermenstrual or postcoital bleeding

Causes & Risk Factors

The FIGO PALM-COEIN system is the internationally accepted standard for classifying the causes of AUB in non-pregnant women of reproductive age.
P - Polyp: Benign growths in the lining of the uterus (endometrial polyps) or cervix.
A - Adenomyosis: A condition where the tissue that normally lines the uterus grows into the muscular wall of the uterus.
L - Leiomyoma (Fibroids): Benign smooth muscle tumors of the uterus. Submucosal fibroids (those that project into the uterine cavity) are most commonly associated with AUB.
M - Malignancy and Hyperplasia: Precancerous changes (endometrial hyperplasia) or cancer of the uterine lining (endometrial carcinoma). These are less common in reproductive-aged women but must be considered in high-risk individuals.
C - Coagulopathy: Systemic bleeding disorders, such as von Willebrand disease, which can affect blood clotting.
O - Ovulatory Dysfunction: Problems with ovulation due to hormone imbalances. Common causes include Polycystic Ovary Syndrome (PCOS), thyroid disease, high prolactin levels, stress, obesity, and perimenopause.
E - Endometrial: Primary disorders of the uterine lining itself, where bleeding is predictable and cyclic but heavy. This may be related to issues with local blood clotting or inflammation within the endometrium.
I - Iatrogenic: Bleeding caused by medical interventions. Examples include certain medications like anticoagulants, some hormonal contraceptives (e.g., breakthrough bleeding with progestin-only methods), copper or hormonal IUDs, and other medications that interfere with hormone metabolism.
N - Not yet classified: Rare causes or conditions that are not yet well-defined, such as arteriovenous malformations (abnormal connections between arteries and veins).
Age: Adolescence (due to an immature hypothalamic-pituitary-ovarian axis) and perimenopause (due to declining ovarian function and anovulatory cycles).
Inherited bleeding disorders, such as von Willebrand disease.
Genetic predisposition, such as a family history of fibroids or endometriosis.
Obesity: A significant risk factor for anovulatory bleeding due to hormone imbalances.
Smoking: Can affect hormone levels and menstrual cyclicity.
Extreme weight loss or gain, excessive exercise, or high stress: Can lead to hormone regulation problems and anovulation.
Medications: Anticoagulants, certain hormonal therapies, some antidepressants, and antipsychotics.

Diagnosis

Medical History: Your doctor will ask about your bleeding pattern (frequency, regularity, duration, volume, clots), associated symptoms (pain, pressure, postcoital bleeding), medical history (bleeding disorders, endocrine disorders), surgical history, medication use, reproductive history (contraception, possibility of pregnancy), and the impact on your quality of life.
Physical Examination: This includes a general exam to check for signs of anemia or systemic disease, and a pelvic exam. A speculum exam allows visualization of the cervix and vagina, while a bimanual exam assesses the uterus and ovaries.
Laboratory Tests: A urine or serum hCG test is mandatory to exclude pregnancy in all reproductive-aged women. A Complete Blood Count (CBC) checks for anemia. Thyroid-Stimulating Hormone (TSH) screens for thyroid dysfunction. Coagulation studies may be performed if a bleeding disorder is suspected, especially if heavy bleeding started at menarche. Cervical cancer screening (Pap test/HPV test) is done as per standard guidelines.
Transvaginal Ultrasound (TVS): This is the first-line imaging method to evaluate for structural abnormalities like fibroids, polyps, adenomyosis, and to measure the thickness of the uterine lining.
Saline Infusion Sonohysterography (SIS): This procedure involves injecting saline into the uterus during an ultrasound to provide a clearer view of the uterine cavity and identify lesions like polyps or submucosal fibroids.
Magnetic Resonance Imaging (MRI): Not a first-line test, MRI is used for preoperative planning for fibroids, complex cases, or when ultrasound results are inconclusive, particularly for suspected adenomyosis.
Endometrial Biopsy: Tissue sampling from the uterine lining is performed to check for hyperplasia (precancerous changes) or malignancy. It is indicated for all women over 45 with AUB, and for women under 45 with AUB who have risk factors (e.g., obesity, PCOS), failed medical management, or persistent AUB. All cases of postmenopausal bleeding require investigation.
Hysteroscopy with Dilation and Curettage (D&C): This procedure allows direct visualization of the uterine cavity and targeted biopsy. It is considered the gold standard for evaluating intracavitary pathology.

Treatment Options

Emergency Treatment (for acute AUB): The goal is to control bleeding and stabilize your condition. This may involve fluid resuscitation, high-dose intravenous conjugated estrogen, high-dose oral progestins or combination oral contraceptives, or tranexamic acid. Surgical options for acute bleeding include Dilation and Curettage (D&C), uterine tamponade, or, in refractory cases, endometrial ablation, uterine artery embolization, or hysterectomy.
Medical Treatment (for chronic AUB):
Hormonal options include: Levonorgestrel-releasing Intrauterine System (LNG-IUS), which is highly effective for heavy menstrual bleeding; Combination Oral Contraceptives (COCs) to regulate cycles and reduce flow; Oral Progestins (cyclic or continuous) for anovulatory bleeding; Depot Medroxyprogesterone Acetate (DMPA) injection; and GnRH Agonists/Antagonists, which induce a temporary medical menopause and are used short-term, often before surgery.
Non-Hormonal options include: Tranexamic Acid (TXA), taken only during menstruation, which reduces bleeding by 30-60%; and Nonsteroidal Anti-inflammatory Drugs (NSAIDs) like mefenamic acid or ibuprofen, taken only during menstruation, which reduce bleeding by 20-50%.
Surgical Treatment:
Endometrial Ablation: Destroys the uterine lining and is suitable for women who have completed childbearing. It has high satisfaction rates but may require re-treatment.
Uterine Artery Embolization (UAE): A minimally invasive procedure for treating fibroids.
Myomectomy: Surgical removal of fibroids while preserving the uterus.
Hysterectomy: Surgical removal of the uterus, which is the definitive treatment for AUB.
Referral Indications: You may be referred to a specialist if there is suspicion of malignancy, if initial medical management fails, if you desire surgical intervention, for complex pathology (e.g., large fibroids), or for acute, uncontrollable hemorrhage.

Frequently Asked Questions

What is considered a "normal" period?

A normal period typically occurs every 24 to 38 days, lasts for 2 to 8 days, and involves a moderate amount of blood loss.

How do I know if my bleeding is too heavy?

Your bleeding might be too heavy if you soak through one or more pads or tampons every hour for several hours, need to change protection during the night, pass blood clots the size of a quarter or larger, or bleed for longer than 7-8 days. Symptoms of anemia like tiredness or shortness of breath can also indicate heavy bleeding.

What is causing my abnormal bleeding?

Abnormal uterine bleeding can be caused by structural issues in the uterus (like polyps, adenomyosis, fibroids, or precancerous/cancerous changes) or non-structural issues (like bleeding disorders, problems with ovulation, issues with the uterine lining, or side effects from medications or IUDs).

Is my heavy bleeding a sign of cancer?

While less common in reproductive-aged women, heavy bleeding can sometimes be a sign of precancerous changes (endometrial hyperplasia) or endometrial cancer, especially if you are over 45 or have risk factors like obesity or PCOS. Any bleeding after menopause always requires investigation to rule out cancer.

Do I need to have a test for every possible cause?

Your doctor will start with a thorough medical history and physical exam. Based on your symptoms and risk factors, they will recommend specific tests, such as blood tests, ultrasound, or possibly a biopsy, to identify the most likely cause without unnecessary testing.

What is a transvaginal ultrasound and is it painful?

A transvaginal ultrasound uses a small probe inserted into the vagina to get clear images of your uterus and ovaries. It is generally not painful, though you might feel some pressure. It's a common and safe first-line imaging test.

Will I need an endometrial biopsy?

An endometrial biopsy is typically recommended for all women over 45 with abnormal uterine bleeding. For women under 45, it may be needed if you have risk factors for endometrial cancer (like obesity or PCOS), if medical treatments haven't worked, or if your abnormal bleeding is persistent. It is also indicated for any bleeding after menopause.

What are the non-hormonal treatment options for heavy bleeding?

Non-hormonal options include Tranexamic Acid (TXA), which reduces blood loss when taken during your period, and Nonsteroidal Anti-inflammatory Drugs (NSAIDs) like ibuprofen, which can reduce bleeding and pain during your period.

What are the side effects of the hormonal IUD (Mirena)?

The dossier highlights that the Levonorgestrel-releasing Intrauterine System (LNG-IUS) is highly effective for heavy menstrual bleeding, reducing bleeding by up to 97%. Specific side effects are not detailed in the provided information.

Can I still get pregnant if I have abnormal uterine bleeding?

Yes, depending on the cause of your AUB. If your AUB is due to ovulation problems, it might affect your ability to conceive. Some causes, like fibroids, can also impact fertility.

Will treatment for AUB affect my fertility?

Some treatments, like endometrial ablation or hysterectomy, are for women who have completed childbearing and will prevent future pregnancies. Other treatments, like hormonal medications or myomectomy (fibroid removal), can preserve or even improve fertility, depending on the underlying cause.

What is the difference between an endometrial ablation and a hysterectomy?

Endometrial ablation destroys the lining of the uterus and is for women who have completed childbearing, aiming to reduce or stop bleeding while keeping the uterus. A hysterectomy is the surgical removal of the entire uterus and is a definitive treatment that ends menstruation and prevents future pregnancies.

Am I too young/old for a hysterectomy?

The decision for a hysterectomy is based on your medical condition, symptoms, desire for future childbearing, and other treatment options, rather than a strict age limit. It is a definitive treatment considered when other options are not suitable or have failed.

If I have fibroids, do they need to be removed?

Not all fibroids need to be removed. Treatment depends on their size, location, and whether they are causing significant symptoms like heavy bleeding or pain. Options range from medical management to procedures like uterine artery embolization or myomectomy (fibroid removal) if symptoms are severe.

Can lifestyle changes like diet and exercise help my bleeding?

Yes, maintaining a healthy body weight through diet and exercise can help prevent abnormal uterine bleeding, especially if it's related to ovulation problems caused by obesity or extreme weight fluctuations. Managing stress can also be beneficial.

Is it safe to use tranexamic acid?

Tranexamic acid is an antifibrinolytic agent that reduces bleeding. It is generally considered safe when used as directed, but like all medications, it has potential side effects. Your doctor will determine if it's appropriate for you.

How long will I need to be on medication?

The duration of medication for chronic abnormal uterine bleeding varies depending on the underlying cause, the type of medication, and your response to treatment. Some medications may be used long-term to manage symptoms, while others might be used for a specific period.

What are the signs that I should go to the emergency room for my bleeding?

You should go to the emergency room if you experience severe, profuse vaginal bleeding (soaking more than one pad per hour), dizziness, lightheadedness, fainting, a rapid heart rate, low blood pressure, unusual paleness, or shortness of breath. These can indicate acute, severe blood loss.

Can my abnormal bleeding be related to perimenopause?

Yes, abnormal uterine bleeding is common during perimenopause due to declining ovarian function and irregular ovulation.

If I have PCOS, will my bleeding always be irregular?

Polycystic Ovary Syndrome (PCOS) is a common cause of ovulatory dysfunction, which often leads to irregular, unpredictable bleeding. However, with appropriate management, including lifestyle changes and medications, menstrual regularity can often be improved.

What is adenomyosis and how is it treated?

Adenomyosis is a condition where the tissue that normally lines the uterus grows into the muscular wall of the uterus. It can cause heavy and painful periods. Treatment options vary and may include pain relief, hormonal therapies, or surgical options like hysterectomy in severe cases.

Does having a D&C fix the bleeding problem permanently?

Dilation and Curettage (D&C) can be both diagnostic and therapeutic for acute heavy bleeding, providing temporary relief and tissue for examination. However, it does not always permanently fix the underlying cause of chronic abnormal uterine bleeding, and symptoms may recur.