Medical doctors have likened endometriosis to a sandstorm that reaches everywhere and goes nowhere. However, just as the herd in the late Eastern Han Dynasty ended up in Wei, Shu and Wu, the symptoms of endometriosis mostly ended up in three major problems: pain, infertility and pelvic masses. The distribution of endometriosis (endo) in the body can be said to be almost ubiquitous, in order of ovaries, the rectal fossa of the uterus, and the pelvic peritoneum, which some have likened to a sandstorm in the pelvis. In addition to the pelvic cavity, endometriosis can also occur in the abdominal wall incision, bladder, cervix, fallopian tubes, intestinal wall, vulva, and vagina. Foci of endoheterosis have also been reported in the retina of the eye, nasal cavity, lung, and pleura. Endothelia is usually classified into peritoneal, ovarian, and deep nodal types. The peritoneal type is the most common form of endograft and is widely distributed in the pelvic abdominal peritoneum. The ovarian type is also common and can form ovarian endometriotic cysts, or “chocolate cysts,” whose contents are not really chocolate, but are named for the accumulation of intracapsular fluid that resembles chocolate juice as a result of bleeding from the endometriosis site. Deep nodules are hard nodules formed in or near the vaginal-rectal septum, which may cause significant lumbosacral pain, anal pain, or painful intercourse. I. There are 3 main types of endometriosis of the peritoneum 1. Red lesions The peritoneum is red lesions, flame-like, densely vascularized, or with glandular-like abnormalities. This indicates abundant neovascularization, active glands and interstitium, and is an early lesion of endoheterosis. 2. Brown lesions or black lesions, which are wrinkled black lesions with cinder-like spots, plaques, and purple nodules. This is due to the repeated bleeding and pigmentation of endoheterotropic lesions, and is a progressive change in endoheterotrophy. 3, white lesions The peritoneum is white and cloudy, with peritoneal defects, scar formation, few glands and interstitium, and reduced vascularity. This is a healing lesion, once called “advanced lesion”, but it is easily associated with the advanced stage of cancer, some people are very nervous, but in fact it is the inactive, fibrotic stage of endoheterosis, does not mean that the disease is more serious. However, it does not respond well to drug therapy because of reduced vascularity and lack of hormone receptors. The evolution of endoheteropathy is often a mixture of various lesions in the pelvic and abdominal cavities of the same patient, the so-called “old, middle and young” or even “four generations in one”. Studies have shown that endoperitoneal heterogeneity changes progressively with age, with simple papular lesions occurring at an average age of 21.5 years, followed by red, black, and white lesions, with black and white lesions mostly manifesting in older women. This suggests that early lesions of endometriosis tend to occur at the beginning of the reproductive years, after which the lesions either disappear or develop, so endometriosis should be detected and treated early to have a better outcome. These pathological changes can lead to a variety of symptoms, which in general can be summarized into three main problems, namely pain, pelvic mass and infertility. The first major problem of endo is pain Endo can cause a wide variety of pain: 87.7% have dysmenorrhea; 71.3% have lower abdominal pain, 57.4% have total abdominal pain, 56.2% have painful intercourse, 42.6% have anal pain, and 39.5% have painful defecation. The most typical and common pain is dysmenorrhea – pain predominantly in the lower abdomen before and after the menstrual period. Dysmenorrhea caused by endometriosis is called “secondary progressive” dysmenorrhea. This means that menstrual cramps do not occur at the beginning of menstruation and in the following years, and then they begin to occur with increasing severity. The degree of dysmenorrhea can be mild or severe, and in mild cases it may be just a swelling in the lower abdomen that relieves itself. In severe cases, the pain is so severe that it hits the wall and seriously affects the patient’s life and work. Pain is currently evaluated using what is called the Visual Analgesia Scoring System (VAS). To determine the level of pain, the doctor will take out a pain score with different colored and scored scales along with a pattern ranging from a smiley face to a crying face and ask the patient to name the area corresponding to the severity of his or her pain. The second type of pain caused by endometriosis is chronic lower abdominal pain. The pain may or may not be related to the menstrual cycle, may or may not be severe, and is often misdiagnosed as chronic pelvic inflammatory disease. The third type of pain caused by endometriosis is painful intercourse, more specifically deep intercourse pain. In other words, pain somewhere deep in the woman’s body during sexual intercourse. This is the type of pain characteristic of endo, and it can also be very painful when the doctor’s hand touches a certain area during a gynecological examination. This area is usually the posterior wall of the uterus, the rectal fossa of the uterus, or the uterosacral ligament. Suffice it to say that if a mass is found in the pelvis, and if it feels painful when the doctor examines it, then it is usually benign, meaning that it may be endometriosis. If it is not painful to the touch, the situation may be bad instead. Another type of pain associated with endometriosis is acute lower abdominal pain. This is usually the result of a ruptured ovarian endometriosis (ovarian chocolate cyst). The so-called ovarian chocolate cyst is a chocolate-like substance formed when the blood in the cyst coagulates after monthly bleeding from the ovarian endometriosis (if the Chinese name is used, it may be named “hairy blood cyst”, which is more similar). The rupture of a chocolate cyst usually occurs in the second half of the menstrual period, before the onset of menstruation. Its main manifestation is pain, but at the same time there is a strange manifestation: the pain is accompanied by stable vital signs. This is not the same as intra-abdominal bleeding that can trigger shock caused by ectopic pregnancy and ruptured corpus luteum, and can thus be differentiated. Acute pain due to ruptured chocolate cysts usually requires hospital examination and, if necessary, surgery, with laparoscopy currently considered to be the best option. The second major problem of endo is infertility It is usually believed that the cause of 50% of infertility can be attributed to endo. It can also be said that about half of the patients with endometriosis are likely to experience infertility. There are many causes of infertility due to endometriosis, which may be a problem with the ovarian function itself or with the abdominal microenvironment, but interestingly, it is usually not a problem with blocked fallopian tubes, which are patent in the vast majority of endometriosis patients. Fourth, the third major problem of endo is pelvic masses The most common mass is an ovarian chocolate cyst. Although endometriosis can occur in several parts of the body, the ovaries remain the most commonly involved site of endometriosis. After the formation of the lesion, the chocolate cyst will gradually grow due to recurrent lesion bleeding once a month. During the growth process, the cyst can rupture if there is too much tension. If the contents are large or the rupture is large, it will lead to acute severe abdominal pain; if the cyst is small or the rupture is small, the rupture can close naturally, but the fluid flowing out of the cyst will cause adhesions between the cyst and the surrounding organs. When examined by a doctor, the mass is very immobile, unlike other benign tumors of the ovary. There is another type of endometriosis mass that occurs in the area between the vagina and the rectum (vagino-rectal septum) or in the ligament at the lower end of the uterus (uterosacral ligament). This deep nodular type of endometriosis often causes severe painful intercourse. The diverse symptoms of endometriosis can basically be summarized in these three major problems. The treatment focuses on each of these three problems. Endometriosis is a benign lesion, and studies to date have found few histomorphologic differences between ectopic and in situ endometrium. In a nutshell, ectopic focal cells are not cancer cells. However, a very small number of endometrioses do become malignant, about 1%, mainly ovarian endometriotic cysts. It is difficult to predict or detect malignancy at an early stage, but it is important to be vigilant in the following cases: (1) postmenopausal pelvic mass in women with a history of endometriosis; (2) ovarian endometriosis cysts >10 cm in diameter or with a tendency to increase significantly; (3) serum CA125 >200 U/ml; (4) imaging reveals substantial structures or papillae within the cyst (gynecologists should be able to examine the cysts during surgery); (5) endometriosis cysts are not cancerous. The gynecologist should be in the habit of cutting down the mass for review during surgery, noting whether there is a solid part of the cyst or an endogenous papilla, and sending frozen sections for examination if necessary); (5) the patient has a change in pain rhythm, such as not only during menstruation.