Symptoms that occur during menstruation:

 Abundant menstrual flow (menorrhagia)
 Menstruation that lasts more than 8 days
 Menstruating early (before 11 years)
 Dysmenorrhea (painful menstruation) – pain generally occurs during the second day of menstruation, then progressively worsen. Menstrual cramps can begin before menstruation, persist for several days and may be associated with back pain or abdominal pain.
 Back pains a day or two days before the start of menstrual period (or later), becoming lighter during the menstrual period.

Other symptoms that occur less frequently and usually occur around ovulation (sometimes unrelated to the menstrual cycle):
 Bleeding outside the menstruation period
 Pain triggered by changing the position
 Other lower limb pain or bladder pain
 Pain during intercourse (dyspareunia)
 Urinary problems
 (Sometimes) blood in urine or stool
 Rectal pain
 Pain during bowel movement

The appearance of pain, its repeatability and/or worsening are clues that may lead to the diagnosis of endometriosis.

The most common and important symptom of this disease is chronic recurring pain. But the pain felt by the individual patient is independent of disease advancement. Other more common symptoms are pelvic pain following a medical examination or after sexual intercourse, including heavy menstruation, dysmenorrhea, back pain, pelvic or abdominal pain, constipation, diarrhea, pain or blood loss when the patient uses the toilet (the unremoved tissue presses on the rectum , intestines or bladder, causing pain or abnormal bleeding), nausea, vomiting episodes, sterility or reduced fertility, feeling tired or gastrointestinal upset that can be confused with other conditions.

Endometriosis can affect any woman from puberty until the postmenopausal period, regardless of race, ethnicity or number of previous pregnancies. Endometriosis persists even after menopause and in rare cases, girls may develop the disease even before they have their first menstruation.