What is endometriosis? A Mayo Clinic expert explains
Learn more about endometriosis from Megan Wasson, D.O., a minimally invasive gynecologic surgeon at Mayo Clinic.
Hi, I'm Dr. Megan Wasson, a minimally invasive gynecologic surgeon at Mayo Clinic. In this video, we will cover the basics of endometriosis, including what is it, who gets it, as well as the symptoms, diagnosis and treatment. Whether you are looking for answers for yourself or someone you love, we are here to give you the best information available. Endometriosis is a condition in which cells similar to the lining of the uterus, or endometrium, grow outside the uterus. Endometriosis often involves the pelvic tissue and can envelop the ovaries and fallopian tubes. It can affect nearby organs, including the bowel and bladder. So during the menstrual cycle, or period, this tissue responds to hormones, and due to its location, frequently results in pain. Endometriosis causes surrounding tissues to become irritated and potentially develop scars and sticky fibers that bind tissues together. In some cases, endometriosis can cause cysts on the ovaries. These are called endometriomas. Fortunately, there are effective treatments to manage and treat endometriosis.
Who gets it?
There are some possible explanations of what sparks the endometrial-like tissue to grow out of place. But the exact cause is still uncertain. However, there are some factors that make someone more likely to get endometriosis, such as never giving birth, menstrual cycles occurring more frequently than every 28 days, heavy and prolonged menstrual periods that lasts longer than seven days, having higher levels of estrogen in your body, having a low body mass index, having a structural issue with the vagina, cervix, or uterus that prevents the passage of menstrual blood from the body, a family history of endometriosis, starting your period at an early age, or starting menopause at an older age.
What are the symptoms?
The most common symptom of endometriosis is pelvic pain, either during or outside of the normal menstrual period that is beyond normal cramping, Normal menstrual cramping should be tolerable and should not require someone to miss time from school, work or normal activities. Other symptoms include cramps that begin before and extend after a menstrual period, lower back or abdominal pain, pain with intercourse, pain with bowel movements or urination, and infertility. Individuals with endometriosis may experience fatigue, constipation, bloating, or nausea, especially during periods. If you are feeling these symptoms, it's a good idea to talk to your health care provider.
How is it diagnosed?
First, your provider will ask you to describe your symptoms, including the location of the pelvic pain. Next, they may do a pelvic exam, an ultrasound, or an MRI to get a clearer view of the reproductive organs, including the uterus, ovaries, and fallopian tubes. To definitively diagnose endometriosis, surgery is required. This is most commonly performed by laparoscopy. The patient is under general anesthesia while the surgeon inserts a camera into the abdomen through a small incision to evaluate for endometrial-like tissue. Any tissue that looks like endometriosis is removed and examined under the microscope to confirm the presence or absence of endometriosis.
How is it treated?
When it comes to treating endometriosis, first steps involve trying to manage symptoms through pain medications or hormone therapy. Hormones, such as birth control pills, control the rise and fall of estrogen and progesterone in the menstrual cycle. If those initial treatments fail and symptoms are impacting a person's quality of life, surgery to remove endometriosis tissue may be considered.
Dealing with endometriosis, its pain, complications and fertility problems can be hard to cope with and be stressful. Consider joining a support group of people who can relate to what you are going through. If you'd like to learn even more about endometriosis, watch our other related videos or visit mayoclinic.org. We wish you well.
With endometriosis, bits of the uterine lining (endometrium) — or similar endometrial-like tissue — grow outside of the uterus on other pelvic organs. Outside the uterus, the tissue thickens and bleeds, just as typical endometrial tissue does during menstrual cycles.
Endometriosis (en-doe-me-tree-O-sis) is an often painful disorder in which tissue similar to the tissue that normally lines the inside of your uterus — the endometrium — grows outside your uterus. Endometriosis most commonly involves your ovaries, fallopian tubes and the tissue lining your pelvis. Rarely, endometrial-like tissue may be found beyond the area where pelvic organs are located.
With endometriosis, the endometrial-like tissue acts as endometrial tissue would — it thickens, breaks down and bleeds with each menstrual cycle. But because this tissue has no way to exit your body, it becomes trapped. When endometriosis involves the ovaries, cysts called endometriomas may form. Surrounding tissue can become irritated, eventually developing scar tissue and adhesions — bands of fibrous tissue that can cause pelvic tissues and organs to stick to each other.
Endometriosis can cause pain — sometimes severe — especially during menstrual periods. Fertility problems also may develop. Fortunately, effective treatments are available.
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The primary symptom of endometriosis is pelvic pain, often associated with menstrual periods. Although many experience cramping during their menstrual periods, those with endometriosis typically describe menstrual pain that's far worse than usual. Pain also may increase over time.
Common signs and symptoms of endometriosis include:
- Painful periods (dysmenorrhea). Pelvic pain and cramping may begin before and extend several days into a menstrual period. You may also have lower back and abdominal pain.
- Pain with intercourse. Pain during or after sex is common with endometriosis.
- Pain with bowel movements or urination. You're most likely to experience these symptoms during a menstrual period.
- Excessive bleeding. You may experience occasional heavy menstrual periods or bleeding between periods (intermenstrual bleeding).
- Infertility. Sometimes, endometriosis is first diagnosed in those seeking treatment for infertility.
- Other signs and symptoms. You may experience fatigue, diarrhea, constipation, bloating or nausea, especially during menstrual periods.
The severity of your pain may not be a reliable indicator of the extent of your condition. You could have mild endometriosis with severe pain, or you could have advanced endometriosis with little or no pain.
Endometriosis is sometimes mistaken for other conditions that can cause pelvic pain, such as pelvic inflammatory disease (PID) or ovarian cysts. It may be confused with irritable bowel syndrome (IBS), a condition that causes bouts of diarrhea, constipation and abdominal cramping. IBS can accompany endometriosis, which can complicate the diagnosis.
When to see a doctor
See your doctor if you have signs and symptoms that may indicate endometriosis.
Endometriosis can be a challenging condition to manage. An early diagnosis, a multidisciplinary medical team and an understanding of your diagnosis may result in better management of your symptoms.
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Although the exact cause of endometriosis is not certain, possible explanations include:
- Retrograde menstruation. In retrograde menstruation, menstrual blood containing endometrial cells flows back through the fallopian tubes and into the pelvic cavity instead of out of the body. These endometrial cells stick to the pelvic walls and surfaces of pelvic organs, where they grow and continue to thicken and bleed over the course of each menstrual cycle.
- Transformation of peritoneal cells. In what's known as the "induction theory," experts propose that hormones or immune factors promote transformation of peritoneal cells — cells that line the inner side of your abdomen — into endometrial-like cells.
- Embryonic cell transformation. Hormones such as estrogen may transform embryonic cells — cells in the earliest stages of development — into endometrial-like cell implants during puberty.
- Surgical scar implantation. After a surgery, such as a hysterectomy or C-section, endometrial cells may attach to a surgical incision.
- Endometrial cell transport. The blood vessels or tissue fluid (lymphatic) system may transport endometrial cells to other parts of the body.
- Immune system disorder. A problem with the immune system may make the body unable to recognize and destroy endometrial-like tissue that's growing outside the uterus.
Several factors place you at greater risk of developing endometriosis, such as:
- Never giving birth
- Starting your period at an early age
- Going through menopause at an older age
- Short menstrual cycles — for instance, less than 27 days
- Heavy menstrual periods that last longer than seven days
- Having higher levels of estrogen in your body or a greater lifetime exposure to estrogen your body produces
- Low body mass index
- One or more relatives (mother, aunt or sister) with endometriosis
- Any medical condition that prevents the passage of blood from the body during menstrual periods
- Disorders of the reproductive tract
Endometriosis usually develops several years after the onset of menstruation (menarche). Signs and symptoms of endometriosis may temporarily improve with pregnancy and may go away completely with menopause, unless you're taking estrogen.
Fertilization and implantation
Fertilization and implantation
During fertilization, the sperm and egg unite in one of the fallopian tubes to form a zygote. Then the zygote travels down the fallopian tube, where it becomes a morula. Once it reaches the uterus, the morula becomes a blastocyst. The blastocyst then burrows into the uterine lining — a process called implantation.
The main complication of endometriosis is impaired fertility. Approximately one-third to one-half of women with endometriosis have difficulty getting pregnant.
For pregnancy to occur, an egg must be released from an ovary, travel through the neighboring fallopian tube, become fertilized by a sperm cell and attach itself to the uterine wall to begin development. Endometriosis may obstruct the tube and keep the egg and sperm from uniting. But the condition also seems to affect fertility in less-direct ways, such as by damaging the sperm or egg.
Even so, many with mild to moderate endometriosis can still conceive and carry a pregnancy to term. Doctors sometimes advise those with endometriosis not to delay having children because the condition may worsen with time.
Ovarian cancer does occur at higher than expected rates in those with endometriosis. But the overall lifetime risk of ovarian cancer is low to begin with. Some studies suggest that endometriosis increases that risk, but it's still relatively low. Although rare, another type of cancer — endometriosis-associated adenocarcinoma — can develop later in life in those who have had endometriosis.
By Mayo Clinic Staff