“On the first two days of my period, I would change my pad every half an hour and still find myself with a sordid, bloody pool on the bed. It was all I could do to writhe and twist [sic]. The pain was excruciating. I often lost between a kilo or two in the first few days of my period every month,” Meher Mirza from Mumbai, who is in her late 30s, told Scroll.in about the pain and fatigue she experiences due to endometriosis since adolescence.

Mirza’s experience resonates with many across the country. The Endometriosis Society of India, a non-profit organization dedicated to creating awareness about the condition, estimates at least 25 million women in India have endometriosis. And yet, it often takes people with the condition, years — and even changing gynecologists — to receive a diagnosis for the poorly understood condition.

What is endometriosis?

Endometriosis is a chronic condition that occurs when the tissue that lines the inside of the uterus — that is, the endometrium — grows outside the uterus. Just like the tissue inside, the tissue outside the uterus thickens, breaks down, and bleeds with each menstrual cycle — but it has no way to exit the body, as the inside tissue does during menstruation. The tissue growing outside the uterus becomes trapped within the body, coating the surface of organs and other tissues, causing them to become inflamed or swollen and leaving scar tissue and lesions.

Endometriosis occurs most commonly on ovaries, Fallopian tubes, the outer surface of the uterus, and ligaments holding the uterus in place. While relatively rarer, endometriosis can also occur on one’s vagina, cervix, vulva, bowel, bladder, or rectum — and even more rarely, on other parts of the body like the lungs, the brain, or even on the skin.

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What are the symptoms of endometriosis?

While some people with endometriosis may not experience any symptoms at all, others experience agonizing pain and discomfort and/or other symptoms that include:

• pelvic pain, especially excessive menstrual cramps
• long-term pain in the lower back
• pain during intercourse
• heavy menstrual bleeding, and/or bleeding between periods
• infertility
• fatigue
• painful, or bloody, urination or bowel movements
• gastrointestinal problems, such as diarrhea, constipation, or nausea

What are the different types and stages of endometriosis?

Experts recognize three types of endometriosis, depending on the part of the body each affects.

• Peritoneal superficial endometriosis occurs when the endometrial tissue attaches itself to the peritoneum, a thin membrane that lines the abdomen and pelvis. This is understood to be the most common, and also the least severe, form of endometriosis.
• Ovarian endometriomas, also called ‘chocolate cysts,’ comprise dark, fluid-filled cysts that occur in different parts of the pelvis or abdomen, but most commonly on the ovaries. Experts note these cysts aren’t very responsive to treatment and can damage healthy tissues.
• Deep infiltrating endometriosis, or D.I.E., affects parts of the body located close to the uterus — like bowels, bladder, or the urinary tract. Reportedly, it makes up about 1 to 5% of endometriosis cases.

Endometriosis is measured in four stages, classified according to severity: minimal, mild, moderate, or severe. While lesions are minimal and isolated in the first stage, in the fourth, they are numerous and can be both superficial and deeply embedded in surrounding tissue.

However, the amount of pain a person may experience doesn’t necessarily correlate with their stage of endometriosis. “You may have a mild form of the disease and yet experience severe pain. It is possible to have a severe form (grades 3 and 4) and be completely asymptomatic or have little discomfort. It is possible for a woman [or person with a uterus] to progress from grade 1 to 3 in a matter of months. It could also take several years for this progression,” Rajeev Punjabi, a gynecologist at Hinduja Hospital in Mumbai, told Scroll.in.

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What causes endometriosis?

The exact causes of endometriosis remain unknown to experts. Experts say a genetic component is likely since endometriosis often runs in families. However, endometriosis can also develop for the first after a C-section, suggesting additional risk factors. Research shows the hormone estrogen promotes endometrial growth, often during early menarche or late menopause, but its exact role in endometriosis isn’t clear. Finally, one popular theory of the origin of endometriosis is retrograde menstruation — which suggests menstrual blood and tissue, containing endometrial cells, flows through the Fallopian tube into other areas of the body, such as the pelvic cavity, and sticks to the organs there.

How is endometriosis diagnosed?

Diagnosing endometriosis is notoriously difficult — on average, it takes seven and a half years for women to be diagnosed. A variety of tests may be used — ranging from a basic pelvic exam to abdominal or transvaginal sonography to an MRI — but the only certain method of diagnosing endometriosis is laparoscopy, a minor surgical procedure that inserts a tiny camera through a cut near the belly button, allowing surgeons to view the abdominal cavity and any endometriotic growths.

How is endometriosis treated?

There is no cure for endometriosis (yet). Once diagnosed, people with the condition may be treated to relieve symptoms, typically through pain medication to control the discomfort, hormone therapy to reduce or stop periods, or surgery either to clear the affected tissue — or in extremely severe cases, to remove the uterus entirely (hysterectomy).