Endometritis: Causes, Symptoms, and Diagnosis

Your uterus is usually a pretty good neighbor: quiet, predictable, and mostly minding its own business. But when germs
make it past the cervix and into the uterine lining (the endometrium), the endometrium can get inflamed and infected.
That condition is called endometritis. It can show up after childbirth, miscarriage, abortion, or certain
proceduresor sometimes as part of a broader pelvic infection. The tricky part? The symptoms can range from “obviously
sick” to “something feels off,” depending on the type and timing.

This guide breaks down what endometritis is, what causes it, what it typically feels like, and how clinicians diagnose
itplus what real-world experiences often look like when people go through the evaluation process.

What Is Endometritis?

Endometritis is inflammation of the uterine lining, most often caused by infection. Clinically, it’s usually discussed
in a few buckets:

• Acute endometritis: starts suddenly and is typically linked to infectionoften associated with sexually
  transmitted infections (STIs) or pelvic inflammatory disease (PID) when not postpartum.
• Postpartum endometritis: a subtype of acute endometritis that happens after delivery (more common after
  cesarean delivery than vaginal delivery).
• Chronic endometritis: longer-lasting inflammation that may be subtle and is sometimes evaluated in the
  context of abnormal bleeding, infertility, or recurrent pregnancy loss.

Endometritis vs. Endometriosis: The Name Trap

These two sound like cousins who borrow your hoodie and never return itbut they’re different conditions.
Endometritis is an infection/inflammation of the uterine lining. Endometriosis is when
tissue similar to the uterine lining grows outside the uterus. They can both cause pelvic pain, but the causes,
diagnosis, and treatment paths are not the same.

What Causes Endometritis?

In most cases, endometritis happens when bacteria (and sometimes other organisms) travel upward from the vagina/cervix
into the uterus. The uterus is not “supposed to be sterile at all times,” but after childbirth or procedures, the usual
barriers can be temporarily weakenedgiving microbes a chance to set up shop where they shouldn’t.

Common Infection Sources and “How Did This Get Here?” Scenarios

• After childbirth (postpartum): especially after cesarean delivery, prolonged labor, prolonged rupture
  of membranes (“water breaking” long before delivery), multiple cervical exams, or infection during labor.
• After miscarriage or abortion: infection risk can increase if tissue remains in the uterus or if
  bacteria enter during or after uterine evacuation.
• After uterine or cervical procedures: examples include dilation and curettage (D&C), hysteroscopy,
  endometrial biopsy, and intrauterine device (IUD) placementanything that involves passing instruments through the
  cervix.
• As part of pelvic inflammatory disease (PID): endometritis can be one piece of PID, which may also
  involve the fallopian tubes and ovaries.

Which Germs Are Usually Involved?

The short answer: it depends on the context.

• Postpartum endometritis is often polymicrobial, meaning multiple bacteria are involved.
  These can include bacteria from the lower genital tract and sometimes the gastrointestinal tract.
• Non-postpartum acute endometritis is frequently associated with STIs, particularly
  chlamydia and sometimes gonorrhea. Bacterial vaginosis–associated bacteria may also
  play a role.
• Less common causes can include tuberculosis (rare in the U.S., but still a recognized
  cause) and other unusual infections depending on a person’s exposures and immune status.

Risk Factors: Who’s More Likely to Get It?

Risk factors aren’t “blame factors.” They’re more like weather forecasts: they help clinicians keep a closer watch
after certain events.

Postpartum risk factors often include

• Cesarean delivery (especially unplanned/emergency cesarean)
• Long time between rupture of membranes and delivery (often > 18 hours)
• Prolonged labor
• Multiple cervical exams during labor
• Infection during labor (for example, chorioamnionitis)
• Internal fetal monitoring
• Placental fragments remaining in the uterus or manual removal of fragments
• Postpartum hemorrhage
• Bacterial vaginosis, anemia, diabetes (in some references)

Non-postpartum risk factors often include

• Untreated or new STI exposure (especially chlamydia or gonorrhea)
• Recent uterine/cervical procedure (D&C, biopsy, hysteroscopy, IUD placement)
• PID risk factors (multiple partners, inconsistent condom use, prior PID)
• In some cases, postpartum-related changes can still matter up to weeks after delivery

Symptoms: What Endometritis Can Feel Like

Symptoms vary based on timing (postpartum vs. not), severity, and whether the infection stays mainly in the uterus or
involves other pelvic structures.

Postpartum Endometritis Symptoms

A classic presentation is a postpartum person who develops fever and uterine tenderness, often within the first few
days after deliverythough later presentations can occur. Symptoms that commonly raise suspicion include:

• Fever (especially postpartum fever without another clear source)
• Lower abdominal or pelvic pain
• Uterine tenderness on exam
• Foul-smelling or purulent lochia (post-birth vaginal discharge)
• Malaise (“I feel hit by a truck”), chills, headache
• Tachycardia (fast heart rate) may accompany fever/infection

Acute Endometritis Outside the Postpartum Period

When endometritis is linked to an STI or PID spectrum, symptoms may include:

• Pelvic pain or lower abdominal pain
• Abnormal vaginal discharge
• Abnormal uterine bleeding (spotting between periods or heavier bleeding)
• Fever (not always present)
• Pain with sex or pain during pelvic exam

Chronic Endometritis: The Quiet Version

Chronic endometritis can be subtlesometimes there are no obvious symptoms. When symptoms occur, they may include:

• Abnormal uterine bleeding (spotting, irregular cycles)
• Pelvic discomfort that’s persistent but not necessarily severe
• Fertility-related concerns (for some people, chronic endometritis is evaluated during workups for
  infertility or recurrent pregnancy loss)

When Symptoms Should Be Treated as Urgent

If you recently gave birth, had a miscarriage/abortion, or had a uterine procedure, seek urgent care (ER/urgent clinic
depending on severity) for:

• High fever, shaking chills, or feeling faint
• Severe or worsening pelvic/abdominal pain
• Heavy bleeding (soaking pads quickly) or passing large clots
• Foul-smelling discharge plus fever
• Shortness of breath, confusion, or signs of dehydration

How Doctors Diagnose Endometritis

Diagnosis is part detective work, part pattern recognition. The goal is to identify endometritis early (because
infections can escalate) while also ruling out other causes of fever, bleeding, and pelvic pain.

Step 1: The Timeline (Timing Is a Huge Clue)

Clinicians start with timing because it narrows the field:

• Within days after delivery: postpartum endometritis rises on the suspect list, especially after
  cesarean delivery or prolonged labor/rupture of membranes.
• After miscarriage/abortion or uterine procedure: clinicians consider uterine infection and whether any
  tissue might remain in the uterus.
• Not postpartum: STI/PID risk and recent sexual history become more relevant; the clinician may think
  “PID spectrum” rather than “isolated uterus problem.”

Step 2: Physical Exam (Including Pelvic Exam)

A pelvic exam helps identify signs of infection and tenderness patterns:

• Uterine/fundal tenderness
• Cervical discharge or signs of cervicitis
• Cervical motion tenderness or adnexal tenderness (more suggestive of PID involvement)
• Assessment of bleeding and discharge

Step 3: Lab Tests (Supporting Evidence and “Rule-Outs”)

No single test diagnoses every case. Instead, clinicians use a mix of targeted tests:

• Pregnancy test (if pregnancy status is uncertain) to guide safe imaging/medication decisions and rule
  out pregnancy-related causes of bleeding.
• Complete blood count (CBC) to look for elevated white blood cells (supportive, not definitive).
• STI testing (often nucleic acid amplification tests/NAATs for chlamydia and gonorrhea), especially
  outside the postpartum period or if PID is suspected.
• Urinalysis/urine culture to rule out urinary tract infection (a common postpartum mimic).
• Inflammation markers like ESR may be used in some settings; they suggest inflammation but aren’t
  specific.
• Wet mount microscopy or other vaginal testing to evaluate discharge patterns and possible bacterial
  vaginosis.

Step 4: Imaging (When Clinicians Need a Look Inside)

Imaging isn’t always required for straightforward postpartum endometritis, because diagnosis is often clinical. But
ultrasound and other imaging can be valuable when:

• Symptoms are severe, persistent, or atypical
• Clinicians suspect retained products of conception (tissue left in the uterus)
• There’s concern for abscess or broader pelvic infection
• PID complications (like tubo-ovarian abscess) are possible

In PID-spectrum cases, clinicians may use transvaginal ultrasound or MRI to look for thickened, fluid-filled tubes,
free pelvic fluid, or tubo-ovarian complex. CT may be used in complicated or unclear cases.

Step 5: Endometrial Biopsy (Mostly for Chronic Endometritis Questions)

Chronic endometritis is commonly evaluated with endometrial biopsy. Pathology may look for features of
chronic inflammation and for plasma cells in the endometrial tissue. Many studies describe using
CD138 (Syndecan-1) immunohistochemical staining to help identify plasma cells more reliably. One important
nuance: diagnostic thresholds and interpretation can vary, and CD138 staining (while helpful) isn’t perfectly
standardized across all labs. In other words, biopsy results should be interpreted in contextsymptoms, fertility history,
and other findings matter.

How Clinicians Rule Out Look-Alikes

Endometritis can resemble other conditions. A careful workup may also consider:

• Postpartum causes of fever: urinary tract infection, wound infection, mastitis, respiratory infections
• Bleeding causes: hormonal irregularity, fibroids, polyps, retained tissue
• Pelvic pain causes: ovarian cysts, appendicitis, endometriosis, GI conditions

What Usually Happens After Diagnosis?

While this article focuses on causes, symptoms, and diagnosis, it helps to know what “next steps” typically look like.
Endometritis is generally treated with antibiotics. Postpartum casesespecially after cesareanoften
require prompt medical treatment and sometimes IV antibiotics, depending on severity. If retained tissue is suspected,
clinicians may address that as well. The key takeaway: if fever and pelvic symptoms appear after a pregnancy-related event
or uterine procedure, getting evaluated quickly can prevent complications.

Experiences Related to Endometritis (Real-World “This Is What It’s Like” Moments)

Medical descriptions can be neat and tidy. Real life is not. Here are common experience patterns that people report
during evaluation for suspected endometritisshared as generalized, educational examples (not personal medical advice).

1) “I Thought Postpartum Felt Like This… Until the Fever Showed Up”

Many postpartum people expect to feel sore, tired, and a little “wrung out,” especially after a long labor or a
C-section. The moment that changes the storyline is often a fever that doesn’t make sense. Someone may notice they feel
chilled even under blankets, or they can’t stop sweating. The belly can feel more tender than expected, and pressing on
the uterus during an exam can be notably painful. A detail that gets mentioned a lot is discharge odorpeople often say,
“It didn’t smell like normal postpartum lochia anymore.” In the clinic or hospital, the experience can feel fast-paced:
vitals, questions about delivery details (“How long after your water broke did delivery happen?”), lab work, and often
quick treatment decisions. Many people describe a strange mix of relief and annoyance: relief that there’s a clear,
treatable reason they feel awful, and annoyance that the timing is so rude (because newborns do not accept “sick day”
requests).

2) “After a Procedure, Something Just Felt Off”

After a D&C, hysteroscopy, or IUD placement, discomfort can happenbut persistent pelvic pain, fever, or abnormal
discharge is the kind of “off” that clinicians take seriously. People often describe second-guessing themselves at first:
“Am I overreacting?” Then symptoms stack up: cramping that doesn’t ease, a fever that shows up later in the day, or
bleeding that feels different than expected. In these scenarios, the diagnostic experience commonly includes a pelvic
exam, a pregnancy test if relevant, STI testing in some cases, and ultrasound if there’s concern for retained tissue.
What stands out emotionally is uncertaintypeople often want one clear test that says yes/no. Instead, they get a
clinical explanation: “This fits the pattern, and we don’t want to wait.”

3) “I Didn’t Feel SickWe Were Investigating Bleeding or Fertility”

Chronic endometritis can enter the conversation in a totally different way. Some people aren’t feverish or acutely ill
at all; they’re dealing with irregular bleeding, persistent spotting, or fertility struggles. The experience here can be
more procedural and less dramatic: an office visit, a discussion about cycle timing, then an endometrial biopsy. People
often describe biopsy day as “not fun, but quick.” What surprises many is the pathology languageterms like “plasma
cells” and “CD138 staining” can sound like sci-fi props. Clinicians usually translate: these are immune cells that
suggest ongoing inflammation in the uterine lining. The real-world vibe is often pragmatic: “If this is contributing,
we want to address it.” And because diagnostic thresholds and interpretations can vary, patients may get nuanced
counseling rather than a black-and-white verdict.

4) “The Most Helpful Part Was Knowing What to Watch For”

Across postpartum, post-procedure, and chronic scenarios, one consistent “experience win” is getting clear red-flag
guidance. People tend to feel calmer when they know exactly what matters: fever, increasing pelvic pain, foul discharge,
heavy bleeding, or worsening overall illness. A practical tip many clinicians emphasize is tracking symptoms with simple
facts: temperature readings, timing, bleeding amount, and whether pain is improving or escalating. It’s not glamorous,
but it helps clinicians quickly understand severity and trajectoryespecially when someone is exhausted, overwhelmed, or
juggling a newborn.

Conclusion

Endometritis is an infection-driven inflammation of the uterine lining, commonly occurring after childbirth (especially
after cesarean delivery), miscarriage/abortion, or uterine proceduresand sometimes as part of PID related to STIs like
chlamydia or gonorrhea. Symptoms often include fever, pelvic pain, uterine tenderness, abnormal bleeding, and
foul-smelling discharge (especially postpartum). Diagnosis is usually based on history, pelvic exam, and targeted tests
to confirm infection and rule out other causes; imaging and endometrial biopsy may be used in selected situations,
particularly when chronic endometritis is suspected. If symptoms appear after delivery or a uterine procedure, prompt
evaluation is importantbecause uterine infections are treatable, but waiting can raise the risk of complications.