#382 Abnormal Uterine Bleeding

February 20, 2023 | By



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With Dr Holly Wong Cummings

Listen in as we talk through abnormal uterine bleeding (AUB) with our esteemed guest Holly Wong Cummings, MD.  We review the PALM-COEIN framework for AUB diagnosis and discuss options for acute and chronic treatment of AUB.  We can get bleeding under control! Many of the treatments including progesterone only pills, combined oral contraceptives, and tranexamic acid are medications we in primary care should feel confident prescribing to our patients.

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Show Segments

  • Intro, disclaimer, guest bio
  • Case from Kashlak
  • Normal Menstrual Cycle
  • Nomenclature for AUB- PALM COEIN
  • History and Physical Exam
  • Laboratory and radiologic evaluation
  • Structural causes for bleeding/interpreting the ultrasound
  • Acute treatment of AUB
  • When to refer to ED
  • Chronic treatment for AUB
  • When to refer to gyn
  • Take home points
  • Outro

Abnormal Uterine Bleeding Pearls

  1. Use the PALM-COEIN framework both to help you with your differential for AUB as well as to be able to communicate with others around the patients’ diagnosis.
  2. Physical exam is important in AUB.  Primary care providers and internists should appreciate the value of performing pelvic examinations.
  3. For most patients with AUB, checking a CBC and TSH is reasonable/appropriate.  
  4. The pelvic ultrasound is the most valuable test for determining the cause of AUB.
  5. Treating acute AUB with either a progesterone alone (ie norethindrone), a combined oral contraceptive pill, or tranexamic acid is effective and should be tailored to patients medical contraindications to estrogen therapies and/or preferences around use of daily vs episodic medication.
  6. For long term treatment of AUB, continuation of acute treatments described above, LARCs like the levonorgestrel IUD or etonogestrel arm implant, or referral to gyn for surgical therapies such as endometrial ablation, myomectomy, or hysterectomy are appropriate options.

Abnormal Uterine Bleeding Notes 

Normal Menstrual Cycle

Cycle day 1 of the menstrual cycle  is the first day of bleeding.  Typical bleeding lasts 5-7 days.   Ovulation occurs typically at day 12-14.  If fertilization does not occur, then typically around day 27-28, the endometrium starts shedding and the cycle restarts.  There is a complex interplay between hormones from the hypothalamus to pituitary to ovaries to trigger ovulation and the build up and shedding of the endometrial lining.

Nomenclature for AUB:

FIGO suggests a standard nomenclature around AUB (abnormal uterine bleeding).  Calling this dysfunctional uterine bleeding (DUB) and terms like metrorrhagia or menometrorrhagia are currently discouraged.  Menorrhagia is still commonly used to describe heavy menstrual bleeding, but the FIGO preferred term is just “heavy menstrual periods”.


Structural causes:

P: Polyps

A: Adenomyosis

L: Leiomyoma (fibroid)

M: Malignancy (or premalignancy/hyperplasia)

Nonstructrual causes

C: coagulopathy

0: ovulatory dysfunction (PCOS, etc)

E: endometrial (chronic endometritis)

I: iatrogenic (anticoagulation, hormonal contraceptives, etc)

N: not otherwise specified.  

Documentation can then briefly explain the situation- ie AUB-L means abnormal bleeding due to fibroids (Munro 2011).  

We have had 2 other great curbsiders episodes covering PCOS (#198) and menorrhagia due to coagulopathy (#280) if you want to learn more about AUB-C, O, and I.


Dr Cummings likes to confirm with the patient that they are counting their days in a standard way- sometimes patients count the day from stopping bleeding to when they start again, instead of from start to next start.  She also likes to get an understanding of their prior cycle history: are there months where the patient is not bleeding at all during a cycle or bleeding in between cycles/intermenstrual bleeding?  She also suggests asking about plans around pregnancy.

Physical Exam

ACP does not recommend routine bimanual exams (Qaseem 2014), but Dr Cummings points out that when a patient presents with abnormal bleeding, this is not a screening/routine exam anymore.  On abdominal exam, sometimes large fibroids can be palpated.  Speculum exam can help you see gross abnormalities on the cervix.  The bimanual exam can help determine the size of the uterus.  Dr Cummings encourages primary care providers and internists to feel comfortable building their skills around pelvic exams.



It is not unreasonable to check a blood count, to rule out anemia.  TSH is valuable as thyroid dysfunction can cause abnormal bleeding.  Ruling out pregnancy is important (Wouk 2019).

Pelvic Ultrasound

A pelvic ultrasound is a standard part of the evaluation for AUB.   Checking this in the follicular phase (after the heaviest bleeding has stopped and before ovulation, when the endometrial lining is thinnest) can be most helpful, but you should not limit getting the ultrasound done at other times in the cycle if scheduling is a challenge.  Dr Cummings does suggest it’s reasonable to defer the ultrasound if you are planning to just start treatment, knowing you can consider checking it in the future.


This test involves a saline infusion through a cervical catheter into the uterus.  Simultaneous ultrasound can image the saline infuse through the uterine cavity and into the fallopian tubes, allowing for a detailed image of the inner uterine cavity.  These are only available in some centers, and in Dr Cummings’ experience not used frequently (ACOG 2012).


A hysterosalpingogram involves injecting dye into the uterus through the cervix under fluoroscopic imaging to assess the passage of dye into the fallopian tubes.  This test is primarily for tubal patency, but can sometimes also reveal details about the endometrial cavity.  In general this is more commonly used for fertility evaluation than in evaluation for AUB.

Endometrial Biopsy

ACOG guidelines suggest in patients over age 45 with AUB, it is appropriate to get an endometrial biopsy (EMB), and consider biopsy in a younger patient with AUB who has risk factors for endometrial hyperplasia such as unopposed estrogen exposure.  Dr Cummings finds shared decision making especially important in these situations.  She suggests allowing the patient to decide if and when they are ready to have the EMB (with ibuprofen before hand, and being emotionally prepared).  An alternative might be a D+C (dilation and curettage) in the operating room if someone is unable to tolerate an in office biopsy.  Dr Cummings agrees because abnormal uterine bleeding is so common in patients with a uterus around perimenopause, many patients can qualify for an EMB.

Dr Cummings approach is that many times patients with AUB who are eligible for EMB are given progesterone as part of their treatment plan, so she is less concerned about missing endometrial hyperplasia as progesterone is a treatment for endometrial hyperplasia, or sometimes even early endometrial cancers.  Progesterone is protective for the endometrial lining (Gompel 2020).

Cervical Evaluation 

Sometimes it can be difficult to differentiate cervical bleeding from uterine bleeding just on history.  Dr Cummings suggests it may be reasonable to get a “diagnostic” pap test, even if someone is up to date on cervical cancer screening, as sometimes vaginal bleeding is not actually uterine bleeding, and we should rule out cervical problems as the cause for bleeding.

Structural Causes for AUB: Ultrasound Findings


Fibroids are very common;  65-75% of people with a uterus may have a fibroid.  These can range from very small (1cm or less) on today’s detailed imaging to people with fibroids so big they rival a full term pregnancy.  Dr Cummings considers a 4-5 cm fibroid small.  Potentially all fibroids can contribute to heavier periods, regardless of size or location.  Fibroids can be pedunculated (hanging off the outside of the uterus), subserosal (within the uterine muscle layer), or submucosal (intracavitary).  Submucosal fibroids may contribute more to heavy bleeding.  

Fibroids can be managed hormonally with oral medications or IUDs.  Referral to gynecology can be helpful if a patient is interested in considering surgical options (Whitaker 2015).


The endometrial cells are within the muscle layer of the uterus instead of being contained within the uterine cavity.  When the lining cells bleed and shed, the endometrial cells within the muscle also bleed and attempt to shed, causing painful and heavy periods (Bourdon 2021).  

Endometrial Thickness

In a postmenopausal patient (>1 year without menses) who presents with bleeding, an ultrasound measured endometrial thickness > or equal to 5mm warrants further evaluation (ACOG 2018).

In a menstruating patient, the endometrial lining will wax and wane significantly through the cycle, there is no specific number that would be concerning.  Dr Cummings suggests that the endometrial stripe can be helpful in predicting ongoing bleeding in the short term- if the endometrial stripe is still thick, the patient likely has significant bleeding ahead.  If the endometrial lining is 2mm, the patient is likely close to being done bleeding.

Endometrial Polyp

Generally, endometrial polyps in patients with AUB are removed given the small risk of hyperplasia or malignancy.  A referral to gynecology can be helpful when polyps are seen (Sheng 2020).

Treatment of AUB


If a patient is severely hemorrhaging (bleeding through >1 tampon/hour, hemodynamic instability, needing a blood transfusion) they should be evaluated in an emergency setting.  In general, patients who are hemodynamically stable do not need emergency room/hospital evaluation, so the majority of patients can be treated as outpatients (ACOG 2012). 

Hormonal treatments and tranexamic acid would not work for something like a polyp, but are effective for other structural and hormonal causes of AUB.

Progestin only medication

Progesterone only treatments, such as medroxyprogesterone or norethindrone, are good options for patients who cannot tolerate oral estrogen (if you’re concerned about VTE risk, etc).  Dr Cummings recommends for severe bleeding, you give a higher dose with a quick taper, ie have a patient take 3 pills for the first day, decrease to 2 pills on day 2, then continue one pill for quicker resolution of bleeding.

Combined Oral Contraceptives

Any of the available options of combined oral contraceptive pills are good options to treat AUB per Dr Cummings opinion.  Typical OCPS are 20-30mcg estrogen.  Sometimes a high dose oral contraception taper (1 pill TID for 1-2 days, then taper down) is used with heavier bleeding to cause a quicker response.  Dr Cummings suggests co-prescribing an antiemetic at the same time if you are recommending higher dose estrogen given significant nausea associated.  She generally reserves this for more severe bleeding- bleeding through a tampon in <1 hour.

Tranexamic Acid

Tranexamic Acid (TXA) is an oral medication that helps clot formation and is highly effective in reducing menstrual bleeding.  This is taken 3 times daily for 5 days during menstrual bleeding (Wellington 2003).   FDA labeling suggests clotting associated with TXA, and cites contraindication to prescribing TXA in patients on hormonal contraceptives or with increased VTE risk.  But, the data is not clear and it may be acceptable to co-prescribe an estrogen containing OCP along with TXA (Relke 2021).

Pro Tips

Dr Cummings discusses options of hormonal medications vs tranexamic acid with patients to help them decide what to take.   Some patients may prefer not to have a daily medication, so TXA might be a good choice.  Tranexamic acid is three times daily but only for the first 5 of bleeding during the month vs hormonal treatment that is daily.  Hormonal treatment is more likely to yield amenorrhea if given enough time.  TXA helps reduce bleeding significantly, but will not yield amenorrhea. 

Never prescribe ongoing estrogen alone because of risk of endometrial hyperplasia.  

Anticipatory guidance is important with prescribing progestins or combined oral contraceptive pills.  Hormonal treatment will stop bleeding, but then if the patient stops the progesterone, there will be a withdrawal bleed.  This bleeding tends to be lighter, and generally less severe than the prior episode.


Continuing oral progestins or combined oral contraceptives used for acute management can prevent future heavy bleeding.  Dr Cummings has noted that patients on long term progesterone therapy may have bothersome side effects, probably more with medroxyprogesterone, including moodiness or bloating.

LARCS (long acting reversible contraceptives) such as levonorgestrel IUD or etonogestrel implant are excellent long term options.

Surgical options can be good choices for patients who are done with child bearing.  An endometrial ablation burns away or ablates the endometrial lining to prevent build up.  A myomectomy can sometimes be an option, though this is less successful for reduction in bleeding, but may be appropriate in patients seeking pregnancy.  A uterine artery embolization done in interventional radiology (IR) can cut off blood flow to parts of the uterus and cause the fibroid to shrink.  Hysterectomy is an option that will certainly resolve bleeding, but is major surgery (ACOG 2013).

Take Home Points

Everyone can do pelvic exams.

Everyone can order a pelvic ultrasound.

Everyone can order oral hormonal medications or tranexamic acid.

If you do those, your patients will be well cared for.


Listeners will feel confident evaluating and treating abnormal uterine bleeding in the primary care setting.

Learning objectives

After listening to this episode listeners will…

  1. Describe a differential diagnosis for causes of abnormal uterine bleeding.
  2. Compare and contrast treatments for heavy uterine bleeding that can be initiated in the primary care setting.
  3. Identify patients who should be referred to specialty gynecology care for treatment


Dr. Holly Wong Cummings reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures. 


Heublein M, Cummings H, Williams PN, Watto MF. “#382 Abnormal Uterine Bleeding”. The Curbsiders Internal Medicine Podcast. https://thecurbsiders.com/episode-list February 20, 2023.

Episode Credits

  • Producer, Writer, Show Notes: Molly Heublein MD
  • Infographic: Edison Jyang
  • Cover Art: Sarah Phoebe Roberts
  • Hosts: Matthew Watto MD, FACP; Paul Williams MD, FACP; Molly Heublein MD
  • Reviewer: Sai S Achi MD, MBA
  • Showrunner: Matthew Watto MD, FACP; Paul Williams MD, FACP
  • Technical Production: PodPaste
  • Guest: Holly Wong Cummings MD

CME Partner


The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit.

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