Endometriosis explained: symptoms, diagnosis, treatment and fertility
A comprehensive overview of endometriosis, including where lesions occur, possible risk factors, tests, treatment choices, pregnancy planning, costs in Japan and follow-up.
What is endometriosis?
Endometriosis is a chronic condition in which tissue resembling the lining of the uterus grows outside the uterine cavity. These growths can contribute to inflammation, adhesions and ongoing pain. It is not an infection that can be passed between people.
It can begin during adolescence and affect people throughout their reproductive years. Some have few noticeable symptoms. The WHO estimates that approximately one in ten women of reproductive age worldwide are affected.
Where can endometriosis develop?
Common sites include the pelvic lining, ovaries and the area between the uterus and rectum. Deep lesions can involve the bowel, bladder or urinary tract; less commonly, growths occur outside the pelvis.
Location partly explains why some people experience pain during bowel movements, urination or other activities. Symptoms vary considerably from person to person.
Causes and associated risk factors
There is no single confirmed cause. Researchers study retrograde menstruation, changes in certain cells and the roles of inflammation, immunity and hormones. Retrograde menstruation occurs in many people who never develop endometriosis.
Family history, early onset of periods and shorter menstrual cycles are associated with increased likelihood in some studies. These associations cannot be used to diagnose an individual, and the condition is not caused by a personal failure.
Symptoms around menstruation
Severe period pain that progressively worsens or disrupts school, work or ordinary activities deserves medical attention. It may occur alongside lower-back pain, nausea, fatigue, bloating or heavy bleeding.
Disabling pain should not be dismissed as an inevitable part of menstruation. However, pain can have several causes, so symptoms alone do not establish the diagnosis.
Symptoms between periods and silent disease
Some experience pelvic pain between periods, pain with bowel movements or urination, pain during sex, or digestive symptoms that fluctuate with the menstrual cycle. Others first learn about the condition during an infertility assessment.
Extensive disease may cause little pain, while small lesions can be associated with substantial symptoms. Having little or no pain does not reliably rule it out.
Ovarian endometriomas
Endometriosis may form a cyst within an ovary, called an endometrioma or sometimes a chocolate cyst. Ultrasound can help identify it and distinguish it from other ovarian cysts.
Size alone does not decide whether an operation is necessary. A specialist considers symptoms, imaging characteristics, complications, age and pregnancy goals. Sudden severe pelvic pain, faintness or persistent vomiting calls for urgent medical evaluation.
When to arrange a gynecology appointment
Seek assessment for increasingly painful periods, recurring pelvic pain, pain affecting daily life, painful bowel or bladder symptoms, or difficulty conceiving. If an ovarian cyst is already known, follow the agreed monitoring schedule.
A symptom diary is useful: record cycle dates, pain location, severity, medication use and impact on daily activities. Even a few cycles of notes can make the consultation more specific.
What happens during an assessment?
A clinician may ask about periods, pain patterns, prior surgery, family history and whether pregnancy is a current goal. An examination may be offered if suitable and with consent. When transvaginal ultrasound is unsuitable or declined, abdominal ultrasound may be discussed.
You can ask why each examination is recommended and describe any discomfort or concerns. Decisions should be made with your informed agreement.
Ultrasound, MRI, CA-125 and laparoscopy
Ultrasound may identify ovarian endometriomas and some forms of deep disease. MRI may clarify the location and extent of suspected deep lesions. A normal scan does not exclude endometriosis, particularly small superficial lesions.
CA-125 can rise for several unrelated reasons and should not be used on its own to diagnose endometriosis. Laparoscopy is sometimes appropriate to assess or treat disease, but it is not always required before treatment can start.
Understanding disease stages
The r-ASRM system describes four stages based on lesions and adhesions documented during surgery. The score describes findings; it does not directly measure how painful the condition is or predict pregnancy for one person.
Someone with early-stage findings may have severe pain. Management should reflect symptoms, imaging, quality of life, fertility priorities and personal preferences rather than stage alone.
Goals of treatment
There is currently no treatment guaranteed to cure endometriosis permanently. Care may focus on reducing pain, improving daily functioning, addressing certain complications or supporting a fertility plan.
Your age, symptoms, health history, test findings, pregnancy goals and possible side effects all matter when choosing an approach. Treatment plans can change as your circumstances do.
Pain relief and hormone treatments
For suitable patients, pain relievers such as certain nonsteroidal anti-inflammatory drugs may help. Hormonal options a clinician might discuss include combined hormonal contraceptives, progestins, a hormonal intrauterine system or treatments affecting GnRH signaling.
Hormone suppression can reduce symptoms but does not improve spontaneous conception when someone is actively trying to become pregnant. Medicines have potential contraindications and side effects, so discuss use and changes with a qualified clinician.
When surgery may be considered
Surgery may be discussed for persistent pain despite appropriate care, deep lesions, selected ovarian cysts or certain fertility situations. Laparoscopy can remove lesions and adhesions, but symptoms and lesions may recur.
Ovarian cyst surgery can reduce ovarian reserve, so there is no universal cyst-size threshold requiring every patient to have surgery. Operating before assisted reproduction does not always improve outcomes. Ask about expected benefit and possible harm before proceeding.
Can someone with endometriosis become pregnant?
Yes. Many people with endometriosis conceive without assistance, although inflammation, adhesions and effects on the ovaries or fallopian tubes can make conception more difficult. Neither the diagnosis nor the disease stage alone predicts an individual's fertility.
For someone trying to conceive, assessment may include ovarian reserve, tubal factors and a partner's fertility. Depending on the situation, options can include observation, selected surgery, intrauterine insemination or IVF. Pregnancy should not be prescribed as a treatment for endometriosis.
Assessment and treatment costs in Japan
In Japan, many medically indicated investigations and endometriosis treatments are eligible for public health insurance under applicable rules. Personal costs vary by age, service, insurance status, provider, hospital stay and whether a treatment is covered.
For larger bills, ask the hospital or insurer about the high-cost medical expense benefit (高額療養費制度), which may limit eligible monthly out-of-pocket spending. Old prices quoted in articles may not reflect current fees or an individual's circumstances.
Long-term follow-up and questions to bring
Symptoms may recur after medication is stopped or after an operation. Follow-up may include reviewing pain and periodic imaging, particularly for ovarian cysts or deep lesions. Tell your clinician if symptoms change or the present plan is no longer working.
Useful questions include: Why is endometriosis suspected? Would ultrasound or MRI help? Can we try treatment without surgery? How could medication affect conception? If surgery is advised, what is the possible impact on ovarian reserve? When should I return? This guide is educational and cannot replace individual diagnosis.