How does endometriosis occur?
Endometriosis develops when endometrial-like mucosal cells normally found in the endometrial lining of the uterus begin growing and functioning in other areas or organs of the body. Under the microscope, endometriosis almost always contains the glands and stroma of normal endometrial cells found in the uterus, but it has other features that are very different; that’s why its cells are described as similar to or endometrial-like.

Despite these microscopic differences, endometriotic growths can respond to the monthly fluctuations of female sex hormones, just as normal uterine endometrial cells do in reproductive-aged women and girls. Because of this, endometriosis growths can bleed, shed, and proliferate in concert with a woman’s monthly menstrual and/or ovulatory cycle. This is why the pain usually becomes most acute around menstruation and/or ovulation.

In the broadest terms, many researchers hypothesize that the body’s immune system recognizes that these endometriotic growths are not growing where they should and therefore launches an immune response in order to destroy them. (Others believe that the immune system does not recognize them until it’s too late). As a result of this continued battle between endometriosis and your body’s immune system, the cytokine-prostaglandin response, inflammation, and other immune system factors appear to become chronically dysregulated.

It’s a classic vicious cycle. Partially as a result of this immune response and other factors, severe pain with menstruation, chronic pain independent of menstruation, inflammation, subfertility, infertility, tissue necrosis, and scar tissue (adhesions) can develop. In severe cases, endometriosis causes such extensive damage that serious complications ensue, like life-threatening bowel obstruction, bladder dysregulation, kidney dysfunction, silent loss of kidney (Ureteral endometriosis), collapsed lungs, and destruction of the ovaries and fallopian tubes. Meanwhile, scar tissue formation also damages organs by encasing them together in abnormal ways -in a sense strangling them – which, in severe cases, leads to the so-called frozen pelvis which can cause chronic pain and even loss of organ function.

Like the rogue agents that they are, it appears that these clever little endometriotic growths can also reprogram genetic pathways, allowing them to continue migrating throughout the body and even produce their own hormones, nerves, and blood supply. It’s as if endometriosis is determined to live and will do anything to ensure its own survival. In this sense, endometriosis behaves in similar ways as cancer, even though it’s classified as a benign condition. (Endometriosis is, however, associated with an increased risk of certain cancers). A combination of genetic predisposition, epigenetic mutations, stem cell dysregulation, immune system dysfunction, and environmental triggers have all been proposed as potential factors in the pathogenesis of endometriosis. Through all of these potential pathways, endometriosis can be a progressive disease; that is, it can continue to grow throughout the body and become worse, despite medical and/or surgical interventions and even if the uterus and ovaries have been surgically removed.

Where does Endometriosis grow?

Endometriosis has been found in every organ and anatomical structure in the body except the spleen. However, the lower abdominal cavity (pelvic cavity) is the most common general area where endometriosis occurs, and the most common cites include the peritoneum (lining of the pelvic area), rectouterine pouch (also called the Pouch of Douglas or or cul-de-sac), rectovaginal septum, rectovaginal septum, uterosacral ligaments, ovaries, fallopian tubes, all over the outside of the uterus, including underneath it and behind it, the appendix, bowel, bladder, and rectum. Meanwhile, adenomyosis, thought to be at least a cousin of endometriosis, if not simply another form of the disorder, occurs inside of the uterus, with the endometrial-like cells growing into the muscular wall of the uterus instead of outside of the uterus, like endometriosis does.

While less common, endometriosis can also grow in other areas, including on blood vessels, the cervix, diaphragm, lungs, nerves, ureters, vagina, and inside of cesarean or other surgical scars.

Rare cases of endometriosis
Although exceedingly rare, endometriosis can even invade other vital organs and structures such as the kidneys, the eyes, liver, pancreas, brain, bone, heart, skin, and nasal cavity.

What the symptoms of Endometriosis?

Although symptoms can vary considerably, the most common are:
extremely painful periods
pain just before or after your period
pelvic pain at any time during the month
pain during or after sexual intercourse
difficulty getting pregnant (infertility)
nausea and vomiting
severe abdominal bloating
pain during ovulation
pain or bleeding with bowel movements
other bowel symptoms (ie, pain with bowel movements/ constipation/ diarrhea intestinal pain/upset stomach)
other bowel/gastrointestinal symptoms (acid reflux, loss of appetite, nausea with eating)
pain or bleeding with urination
other bladder symptoms (difficulty voiding/urgency/frequent urination/ incontinence)
pain in the lower back
pain in the groin area
heavy periods
more frequent periods
other, irregular bleeding
fainting/falling unconscious (due to pain)
pain that mimics appendicitis
pain that mimics celiac disease
pain that mimics Crohn’s Disease and/or irritable bowel syndrome
pain that mimics interstitial cystitis
fatigue

What are the risk factors for Endometriosis?

A woman who has a mother or sister with endometriosis is much more likely to develop endometriosis than other women.

You are also more likely to have endometriosis if you:

Started your period at a young age
Never had children
Have frequent periods or ones that last 7 or more days
Have a closed or otherwise blocked hymen (imperforate hymen, congenital aplasia), which blocks the flow of menstrual blood out of your body during menstruation (also called Mayer-Rokitansky-Kster-Hauser (MRKH) syndrome)
Have other uterine abnormalities such as a double uterus, septate uterus, or bicornuate uterus
Have fibroids

Why Endometriosis is so painful?

Unlike normal endometrial cells found in the lining of the uterus, these errant endometriotic growths do not get expelled from your body each month as a period. Instead, they implant and begin reacting to the monthly hormones that trigger menstruation, causing them to bleed and shed and grow, month after month and year after year if left untreated. Although these endometriotic growths are benign (not cancer), it appears that the body still recognizes that they shouldn’t be growing outside of the uterus, and therefore usually launches an inflammatory response in order to try to destroy them. As a result, the affected areas become extremely inflamed and therefore potentially extremely painful. This chronic pro-inflammatory environment eventually leads to elevated cytokine-prostaglandin levels which contribute to the chronic pain. Blood and pus-filled endometriotic cysts may also form, which can become twisted (called torsion) and/or burst open and cause still more pain, bleeding, infection, and another cascade of acute inflammatory responses. Endometriosis can also grow directly onto nerves, which can cause excruciating pain, similar to the way that the nerve-invading disorder shingles does.

As mentioned, it also appears that endometriotic growths can generate their own supply of blood vessels and nerves, which increases the number of pain receptors and therefore contributes to heightened pain responses. Eventually, scar tissue and other symptoms of endometriosis develop. In fact, scar tissue itself can cause severe pain. For example, in cases when endometriosis has invaded the ureters, scar tissue can cause these organs to close up (constrict), which can lead to severe kidney infections and an inability to completely void when urinating. Bowel endometriosis, on the other hand, can cause severe bowel obstructions and/or tiny perforations (holes), allowing the contents of the bowel to leak out into the pelvic cavity, which can cause an extremely painful, life-threatening medical emergency. In severe cases endometriosis can even completely destroy organs. For example, while most know that endometriosis can totally destroy the ovaries, in rare cases some women have even lost a kidney due to this confounding disorder.

CanEndometriosis be cured?

Some have claimed that endometriosis can be cured by a thorough excision surgery or by pregnancy or hysterectomy or medicines or life style changes. As much as we wish there were a cure, unfortunately, these claims are absolutely untrue. Surgery does not cure endometriosis; lasers do not cure endometiosis; pregnancy does not cure endometriosis; hysterectomy does not cure endometriosis; menopause does not cure endometriosis; birth control pills do not cure endometriosis; dietary changes do not cure endometriosis. There is no cure for endometriosis. The myth that excision surgery by an excision expert can cure endometriosis has persisted because some women do indeed experience a remission of symptoms after one particular surgery, or after a few surgeries that didn’t appear to help, followed by one last surgery, which did. At first glance, this would make it seem as if endometriosis is curable if only one could just get the right surgery. However, there are other women who have a more recalcitrant form of endometriosis, as well as other factors, who, despite having the exact same surgery by the exact same surgeon still experience recurrent endometriosis.

In short, extrapolating the experience of one patient to that of an entire population produces misleading conclusions because women have unique genetic, endocrinologic, and environmental modulators, as well as different forms of endometriosis that vary widely in symptoms and recurrence patterns. Patients with severe, stage IV endometriosis, for example, often have higher recurrence rates than those with less severe disease (stage I-II).

However, what is true is that surgeons have varying degrees of skill and experience, which definitely does make a difference. In fact, as dozens of studies have repeatedly found, the two main factors correlated with successful surgical outcomes are the skill and experience of the surgeon. It is for this reason that women with endometriosis are urged to seek care from an endometriosis specialist.

CanEndometriosis be cured?

There is no cure for endometriosis but a combination of medical and surgical treatment can significant improve the symptoms. Surgical treatment helps to remove all the visible disease while the medical treatment can help to reduce the recurrence and keep the symptoms away.