Medical review status: Editorially reviewed against current ACOG, WHO, NICE, and ESHRE guidance. This article has not been medically reviewed by a gynecologist, endometriosis specialist, reproductive endocrinologist, gastroenterologist, urologist, or other licensed healthcare professional.
Quick Answer: What Are Less-Obvious Endometriosis Symptoms?
Uncommon symptoms of endometriosis can include bowel or bladder symptoms, bloating and nausea, lower-back or radiating pain, persistent fatigue, pain outside the menstrual period, infertility with few other symptoms, and—rarely—chest or breathing symptoms when endometriosis occurs outside the pelvis.
Some of these symptoms are not truly “rare”; they are simply less recognized than severe period pain. WHO notes that endometriosis can affect bowel movements, urination, sexual intercourse, mental health, and areas outside the pelvis, including the abdomen and chest.
A useful clue is whether symptoms are cyclical—for example, bowel, bladder, back, or chest symptoms that repeatedly worsen around menstruation. But a menstrual pattern does not prove endometriosis, and many other conditions can cause the same symptoms.
Symptoms That Need Urgent Medical Assessment
Do not assume a severe symptom is “just endometriosis.” Seek urgent or emergency medical care for:
- chest pain, coughing up blood, or significant shortness of breath
- sudden severe pelvic or abdominal pain
- fainting, severe dizziness, or signs of major blood loss
- very heavy vaginal bleeding
- possible pregnancy with pelvic or abdominal pain and bleeding
- fever with severe pelvic pain or unusual discharge
- inability to urinate or severe urinary symptoms
- new weakness, numbness, or other significant neurological symptoms
Rare thoracic endometriosis can cause cyclical chest symptoms, but chest pain, breathlessness, or coughing blood also have potentially life-threatening causes that must be ruled out first.
Medical and Editorial Notice
This article provides general education. It cannot diagnose endometriosis from a symptom list, menstrual pattern, ultrasound result, or online questionnaire.
Endometriosis symptoms overlap with gastrointestinal, urinary, musculoskeletal, gynecologic, and other conditions. Professional assessment is important when symptoms are persistent, severe, cyclical, worsening, or interfering with daily life.
What Is Endometriosis?
Endometriosis is a chronic condition in which tissue similar to the lining of the uterus grows outside the uterus. The lesions can cause inflammation and scar tissue and may affect the ovaries, pelvic lining, bowel, bladder, ureters, and other areas.
WHO estimates that endometriosis affects about 10% of women of reproductive age worldwide.
Common symptoms include severe menstrual pain, heavy menstrual bleeding, chronic pelvic pain, pain during sex, infertility, bloating, and nausea. Some people have few or no symptoms.
Are these symptoms really “Uncommon”?
Not always.
The search phrase “uncommon symptoms of endometriosis” often refers to symptoms that are less widely recognized by the public rather than medically rare.
For example, bowel and bladder symptoms are specifically recognized in current endometriosis guidance. What makes them easy to miss is that they can resemble IBS, urinary disorders, pelvic-floor problems, or other conditions.
A symptom diary that records pain, bleeding, bowel or bladder changes, and timing within the menstrual cycle can make clinical discussions more useful. NICE specifically recommends symptom and pain diaries as an aid to assessment.
1. Bowel symptoms that worsen around menstruation
Endometriosis can affect the bowel or tissues around it. Possible symptoms include:
- pain during bowel movements
- bloating
- abdominal cramps
- constipation or diarrhea
- nausea
- pelvic or rectal discomfort
A cyclical pattern—symptoms that repeatedly worsen around menstruation—can increase suspicion, but IBS, inflammatory bowel disease, infection, food intolerance, and other gastrointestinal conditions can look similar.
Blood in the stool, unexplained weight loss, fever, persistent vomiting, or severe pain should not automatically be attributed to endometriosis.
For digestive guidance, visit the Digestive Health & Gut Hub.
2. Bladder and Urinary Symptoms
Endometriosis can involve the bladder or ureters and may cause:
- pain with urination
- urinary frequency or urgency
- pelvic pain when the bladder is full
- occasionally blood in the urine
Symptoms that repeatedly worsen around menstruation can be a clue, but urinary tract infection, kidney stones, interstitial cystitis/bladder pain syndrome, pelvic-floor dysfunction, and other conditions are often more common explanations.
Visible blood in the urine, fever, flank pain, inability to urinate, or severe urinary symptoms need medical assessment.
3. Bloating and Nausea
WHO includes abdominal bloating and nausea among recognized endometriosis symptoms.
Some people notice marked abdominal bloating around menstruation. This is sometimes informally called “endo belly,” but that phrase is not a medical diagnosis.
Bloating is extremely nonspecific and can also be caused by constipation, IBS, dietary factors, ovarian conditions, medication effects, pregnancy, or other gastrointestinal and gynecologic problems.
4. Lower-Back or Radiating Pain
Endometriosis-related pelvic pain can sometimes be felt in the lower back or radiate beyond the pelvis.
A repeated menstrual pattern may be useful context, but most lower-back pain has musculoskeletal or other non-endometriosis causes.
New leg weakness, numbness, loss of bladder or bowel control, or severe neurological symptoms require urgent assessment rather than an assumption of endometriosis.
For a broader differential, read What Causes Lower Back Pain in Females?
5. Persistent Fatigue
Fatigue can occur with endometriosis and may reflect chronic pain, disrupted sleep, heavy bleeding, iron deficiency, mental-health burden, treatment effects, or a combination of factors.
WHO notes that endometriosis can significantly affect quality of life and that heavy menstrual bleeding can contribute to iron deficiency and fatigue.
Persistent fatigue also has many other causes, including anemia, thyroid disease, sleep disorders, infection, depression, medication effects, and nutritional problems. It should not be diagnosed as endometriosis from fatigue alone.
6. Pain that continues outside the menstrual period
Endometriosis pain is often associated with menstruation, but it does not have to occur only during a period.
WHO recognizes chronic pelvic pain that continues beyond menstruation as a possible symptom. ACOG also notes that endometriosis may cause pain throughout the month.
Persistent pelvic pain can also occur with adenomyosis, fibroids, pelvic-floor dysfunction, bladder pain syndrome, gastrointestinal conditions, musculoskeletal problems, and other causes.
7. Infertility With Few or No Pain Symptoms
Some people with endometriosis have little or no pelvic pain and first learn about the condition during an infertility evaluation.
ACOG notes that many people without symptoms discover endometriosis when they have difficulty becoming pregnant or during surgery for another reason.
Endometriosis is one of many possible causes of infertility. Male-factor infertility, ovulation disorders, tubal disease, age-related fertility changes, and unexplained infertility also need consideration.
8. Rare Chest, Shoulder, or breathing symptoms
Endometriosis most often affects the pelvis, but WHO confirms that it can occur elsewhere, including the chest.
Thoracic endometriosis is uncommon and may cause symptoms that appear around menstruation, such as chest pain, shoulder pain, shortness of breath, or—in rare cases—coughing blood.
Do not self-diagnose these symptoms as thoracic endometriosis. Chest pain, breathlessness, and coughing blood can indicate pulmonary embolism, pneumothorax, infection, heart disease, or other emergencies.
People with suspected endometriosis outside the pelvis should be referred to specialist services; NICE specifically recommends specialist referral for endometriosis outside the pelvic cavity.
What Conditions Can Be Confused With Endometriosis?
Endometriosis can overlap symptomatically with:
- irritable bowel syndrome
- inflammatory bowel disease
- ovarian cysts
- adenomyosis
- fibroids
- pelvic inflammatory disease
- urinary tract infection
- bladder pain syndrome
- pelvic-floor dysfunction
- musculoskeletal back or hip conditions
Having one of these diagnoses does not automatically rule out endometriosis, and having cyclical symptoms does not automatically prove it.
How Is Endometriosis Diagnosed in 2026?
This is one of the biggest areas where older endometriosis articles are now outdated.
Surgery is no longer required before every patient can receive a working or presumptive diagnosis and begin treatment.
ACOG's March 2026 clinical guidance supports a presumptive clinical diagnosis based on history, symptoms, physical-examination findings, and imaging when appropriate. This can allow empiric treatment while evaluation continues.
WHO likewise states that endometriosis can be diagnosed clinically using symptoms and imaging such as ultrasound or MRI and that surgery is not necessarily required before treatment begins.
NICE recommends carrying out imaging and referral in parallel with initial treatment rather than forcing patients to complete a long sequence of failed treatments before investigation.
What tests are used for suspected endometriosis?
History and Symptom Pattern
The clinician reviews pain, menstrual bleeding, bowel and bladder symptoms, sexual pain, fertility history, family history, and how symptoms change through the menstrual cycle.
Pelvic Examination
A pelvic examination may identify tenderness, nodules, reduced organ mobility, masses, or visible lesions, but a normal examination does not rule out endometriosis.
Ultrasound
NICE's updated guideline recommends offering a transvaginal ultrasound to all people with suspected endometriosis, even when the pelvic or abdominal examination is normal. If transvaginal ultrasound is not suitable, transabdominal ultrasound may be considered.
Ultrasound can identify ovarian endometriomas, some deep endometriosis, and other pelvic conditions. A normal scan does not completely exclude endometriosis.
MRI
Specialist pelvic MRI or specialist ultrasound may be used when deep endometriosis is suspected or its extent needs mapping.
CA-125 and Other Blood Tests
NICE specifically advises not using CA-125 to diagnose endometriosis. Other blood tests may be used to investigate anemia, pregnancy, inflammation, or alternative diagnoses, but there is currently no routine blood test that independently confirms endometriosis.
Laparoscopy
Laparoscopy remains an important diagnostic and treatment option, especially when symptoms persist, imaging is inconclusive, deep disease is suspected, surgery is preferred, or the diagnosis remains uncertain.
But the old claim that laparoscopy is required in every case—or that it has “nearly 100% accuracy”—is too absolute. NICE notes that biopsy may support the diagnosis and that even a negative histology result does not always exclude endometriosis.
How is endometriosis treated?
There is currently no definitive cure. Treatment is individualized according to symptoms, treatment goals, fertility plans, side effects, previous response, disease location, and personal preferences.
Pain Relief
NSAIDs or other analgesics may be used for pain when appropriate. NICE recommends discussing benefits and risks and considering a short trial of paracetamol or an NSAID for endometriosis-related pain.
Hormonal Treatment
Hormonal options can reduce endometriosis-related pain in some people. Depending on the patient and treatment goal, options may include combined hormonal contraception, progestin-based treatment, or GnRH-based medicines.
Surgery
Surgery is not simply a last resort. It is one treatment option that should be discussed according to symptoms, fertility goals, disease location, previous treatment, and patient preference.
Surgery can remove endometriosis lesions, endometriomas, adhesions, or scar tissue, but symptoms can recur, and surgery is not a guaranteed cure.
Supportive Care
WHO notes that multidisciplinary pain approaches—including physiotherapy and cognitive behavioural therapy—may help reduce pain and improve quality of life for some people.
NICE states that current evidence does not support traditional Chinese medicine or Chinese herbal medicines or supplements as treatments for endometriosis.
How Does Endometriosis Affect Fertility?
Endometriosis is associated with infertility, but it does not mean pregnancy is impossible.
WHO estimates that about 25% to 50% of women with infertility have endometriosis. Fertility effects vary with age, ovarian reserve, tubal anatomy, disease location, partner factors, and other causes of infertility.
When pregnancy is a priority, treatment decisions differ. NICE advises against hormonal treatment solely to improve spontaneous pregnancy rates in people with endometriosis who are trying to conceive.
Fertility treatment may include ovulation induction, intrauterine insemination, or IVF in selected cases.
Key Takeaway
Uncommon symptoms of endometriosis often mean less-recognized symptoms rather than truly rare ones.
Bowel and bladder symptoms, bloating, nausea, fatigue, back pain, chronic pelvic pain outside menstruation, and infertility can all occur. Rarely, endometriosis can involve the chest.
A cyclical pattern can help raise suspicion, but symptoms alone cannot diagnose endometriosis.
Current 2026 guidance no longer requires surgical confirmation before every person can receive a presumptive diagnosis or begin appropriate treatment. History, examination, ultrasound, MRI when appropriate, and shared decision-making now play larger roles.
References and Authoritative Sources
- ACOG: Diagnosis of Endometriosis — Clinical Practice Guideline, March 2026
- ACOG: Updated Endometriosis Guidance and Presumptive Clinical Diagnosis, 2026
- ACOG: Endometriosis Patient FAQ
- World Health Organization: Endometriosis — Updated October 2025
- NICE NG73: Endometriosis — Diagnosis and Management, Updated 2024–2026
- ESHRE: Guideline on Endometriosis
Source review date: August 9, 2026
These organizations do not endorse NextFitLife.
Frequently Asked Questions About Uncommon Symptoms of Endometriosis
What are some uncommon symptoms of endometriosis?
Less-recognized symptoms can include bowel or bladder symptoms, bloating, nausea, lower-back or radiating pain, fatigue, chronic pelvic pain outside menstruation, infertility with few other symptoms, and rarely chest symptoms.
Can endometriosis cause bowel symptoms?
Yes. Endometriosis can be associated with painful bowel movements, bloating, abdominal pain, constipation, diarrhea, or nausea. A menstrual pattern can be a useful clue, but gastrointestinal conditions can cause the same symptoms.
Can endometriosis cause urinary symptoms?
Yes. Bladder or urinary-tract involvement can cause pain with urination, frequency, urgency, or occasionally blood in the urine. Infection and other urinary disorders should also be considered.
Can endometriosis cause lower-back pain?
It can contribute to back or radiating pain in some people, but most back pain has other causes. A cyclical pattern may support suspicion but does not prove endometriosis.
Can endometriosis cause fatigue?
Yes. Fatigue may be related to chronic pain, sleep disruption, heavy bleeding and iron deficiency, mental-health burden, treatment effects, or other factors.
Can endometriosis affect the lungs or chest?
Rarely, endometriosis can occur in the chest. Cyclical chest pain, shoulder pain, shortness of breath, or coughing blood requires medical assessment because serious heart and lung conditions can cause similar symptoms.
Can you have endometriosis without severe period pain?
Yes. Some people have mild or no pain and are diagnosed during an infertility evaluation or investigation for another problem.
Does a normal ultrasound rule out endometriosis?
No. Ultrasound can identify ovarian endometriomas and some deep disease, but a normal ultrasound does not completely exclude endometriosis.
Is laparoscopy always required to diagnose endometriosis?
No. Current ACOG and WHO guidance allows a presumptive clinical diagnosis based on symptoms, history, examination, and imaging when appropriate, with treatment sometimes beginning without surgery.
Is laparoscopy nearly 100% accurate?
No. That claim is too absolute. Laparoscopy is an important diagnostic tool, but lesion recognition and biopsy have limitations, and NICE notes that a negative histology result does not always exclude endometriosis.
Can a blood test diagnose endometriosis?
No routine blood test currently confirms endometriosis. NICE specifically recommends not using CA-125 as a diagnostic test for endometriosis.
Is surgery a last resort for endometriosis?
Not necessarily. Surgery is one option that may be appropriate depending on symptoms, disease location, fertility goals, previous treatment, and patient preference. It should be discussed through shared decision-making.
Can herbal remedies treat endometriosis?
Current NICE guidance does not support traditional Chinese medicine or Chinese herbal medicines or supplements as treatments for endometriosis.
Is this article medically reviewed?
No. It was source-checked against current ACOG, WHO, NICE, and ESHRE guidance but has not been medically reviewed by a licensed endometriosis specialist.
Medical Disclaimer
NextFitLife provides general educational information. This article cannot diagnose endometriosis, bowel or bladder disease, infertility, thoracic endometriosis, or another medical condition and cannot replace gynecologic, gastrointestinal, urinary, fertility, or emergency assessment.
Health & wellness writer with 30+ years of experience in nutrition, fitness, and healthy aging. Founder of NextFitLife.com — evidence-based health guidance.
