Endometriosis is a painful disorder in which tissue that normally lines the endometrium (inside of your uterus), grows outside your uterus. Endometriosis involves your fallopian tubes, ovaries and the tissue lining your pelvis. It’s very rare for endometrial tissue to spread beyond pelvic organs.

Endometriosis occurs when displaced endometrial tissue thickens, breaks down and bleeds with each menstrual cycle. This displaced tissue becomes trapped in the body since there is no way for it to exit. When endometriosis involves the ovaries, cysts called endometriomas may form. Surrounding tissue can become irritated, eventually developing scar tissue and adhesions — abnormal bands of fibrous tissue that can cause pelvic tissues and organs to stick to each other.

Endometriosis may cause severe pains especially during your period. Fertility problems also may develop.

Symptoms
The main symptom of endometriosis is pelvic pain, often associated with your menstrual flow. Although many women experience cramping during their menstrual period, women with endometriosis typically describe menstrual pain that’s far worse than usual. They also tend to report that the pain increases over time.

READ ALSO: Painful Menstruation: Causes And Treatment

Common signs and symptoms of endometriosis may include:

Painful periods (dysmenorrhea).Pelvic pain and cramping may begin before your period and extend several days into your period. You may also have lower back and abdominal pain.
Pain during sexual intercourse
Pain with bowel movements or urination: These symptoms may occur during your period
Excessive bleeding:You may experience occasional heavy periods (menorrhagia) or bleeding between periods (menometrorrhagia)
Infertility:Endometriosis is first diagnosed in some women who are seeking treatment for infertility
Other symptoms:You may also experience fatigue, diarrhea, constipation, bloating or nausea, especially during menstrual periods.
The degree of your pain isn’t a reliable indicator of the extent of the condition. Some women with mild endometriosis have experience extreme pain, while others with advanced endometriosis may have little pain or no pain at all.

Endometriosis is at times mistaken for other conditions that can cause pelvic pain, such as ovarian cysts or pelvic inflammatory disease (PID). It may be confused with irritable bowel syndrome (IBS), a condition that causes bouts of diarrhea, constipation and abdominal cramping.

Causes
Possible causes of endometriosis include:

Transformation of peritoneal cells:Experts propose that hormones or immune factors promote transformation of peritoneal cells (cells that line the inner side of your abdomen) into endometrial cells.
Retrograde menstruation: this occurs when menstrual blood containing endometrial cells flows back through the fallopian tubes and into the pelvic cavity instead of out of the body. These displaced endometrial cells stick to the pelvic walls and surfaces of pelvic organs, where they grow and continue to stiffen and bleed over the course of each menstrual cycle.
Embryonic cell transformation: During puberty, hormones such as estrogen may transform embryonic cells (cells in the earliest stages of development) into endometrial cell implants.
Surgical scar implantation:After a surgery, such as a hysterectomy or C-section, endometrial cells may attach to a surgical incision.
Endometrial cells transport:The blood vessels or tissue fluid (lymphatic) system may transport endometrial cells to other parts of the body.
Immune system disorder:This occurs when a problem with the immune system causes the body not to be able to recognize and destroy endometrial tissue that’s growing outside the uterus.
Risk factors
Several factors place you at greater risk of developing endometriosis, such as:

When you have never given birth
Starting your period at an early age
Going through menopause at an older age
Short menstrual cycles — for instance, less than 27 days
Having higher levels of estrogen in your body or a greater lifetime exposure to estrogen your body produces
Low body mass index
Excessive consumption of alcohol
One or more relatives (mother, aunt or sister) with endometriosis
Any medical condition that prevents the normal passage of menstrual flow out of the body
Uterine abnormalities
Endometriosis usually develops several years after the onset of menstruation (menarche). Signs and symptoms of endometriosis end temporarily with pregnancy and end permanently with menopause, unless you’re taking estrogen.

Complications
Infertility
The main complication of endometriosis is impaired fertility. Approximately one-third to one-half of women with endometriosis have issues with getting pregnant.

READ ALSO: Infertility In Men And Women – Causes and Treatment

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 cause obstruction in the tube, thereby preventing egg and sperm from uniting. Endometriosis can also cause damage to the sperm or egg. Many women with mild to moderate endometriosis can still conceive and carry a pregnancy to term.

Ovarian cancer
Ovarian cancer does occur at higher than expected rates in women with endometriosis. However 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.

Source: http://www.healthdiary365.com/2018/01/18/endometriosis-symptoms-causes-and-treatment/