The major cause for distal tubal occlusion is pelvic inflammatory disease (PID), usually as a consequence of an ascending infection by chlamydia or gonorrhea. However, not all pelvic infections will cause distal tubal occlusion. Tubal tuberculosis is an uncommon cause of hydrosalpinx formation.

While the ciliae of the inner lining (endosalpinx) of the fallopian tube beat towards the uterus, tubal fluid is normally discharged via the fimbriated end into the peritoneal cavity from where it is cleared. If the fimbriated end of the tube becomes agglutinated, the resulting obstruction does not allow the tubal fluid to pass; it accumulates and reverts its flow downstream, into the uterus, or production is curtailed by damage to the endosalpinx. This tube then is unable to participate in the reproductive process: sperm cannot pass, the egg is not picked up, and fertilization does not take place.

Other causes of distal tubal occlusion include adhesion formation from surgery, endometriosis, and cancer of the tube, ovary or other surrounding organs.

A hematosalpinx is most commonly associated with an ectopic pregnancy. A pyosalpinx is typically seen in a more acute stage of PID and may be part of a tuboovarian abscess (TOA).

Tubal phimosis refers to a situation where the tubal end is partially occluded, in this case fertility is impeded, and the risk of an ectopic pregnancy is increased.

As pelvic inflammatory disease is the major cause of hydrosalpinx formation, steps to reduce sexually transmitted disease will reduce incidence of hydrosalpinx. Also, as hydrosalpinx is a sequel to a pelvic infection, adequate and early antibiotic treatment of a pelvic infection is called for.

Most commonly a tube may be obstructed due to infection such as pelvic inflammatory disease (PID). The rate of tubal infertility has been reported to be 12% after one, 23% after two, and 53% after three episodes of PID. The Fallopian tubes may also be occluded or disabled by endometritis, infections after childbirth and intraabdominal infections including appendicitis and peritonitis. The formation of adhesions may not necessarily block a fallopian tube, but render it dysfunctional by distorting or separating it from the ovary. It has been reported that women with distal tubal occlusion have a higher rate of HIV infection.

Fallopian tubes may be blocked as a method of contraception. In these situations tubes tend to be healthy and typically patients requesting the procedure had children. Tubal ligation is considered a permanent procedure.

Approximately 20% of female infertility can be attributed to tubal causes. Distal tubal occlusion (affecting the end towards the ovary) is typically associated with hydrosalpinx formation and often caused by "Chlamydia trachomatis". Pelvic adhesions may be associated with such an infection. In less severe forms, the fimbriae may be aggluntinated and damaged, but some patency may still be preserved. Midsegment tubal obstruction can be due to tubal ligation procedures as that part of the tube is a common target of sterilization interventions. Proximal tubal occlusion can occur after infection such as a septic abortion. Also, some tubal sterilization procedures such as the Essure procedure target the part of the tube that is near the uterus..

Most women of reproductive age develop small cysts each month, and large cysts that cause problems occur in about 8% of women before menopause. Ovarian cysts are present in about 16% of women after menopause and if present are more likely to be cancer.

Benign ovarian cysts are common in asymptomatic premenarchal girls and found in approximately 68% of ovaries of girls 2–12 years old and in 84% of ovaries of girls 0–2 years old. Most of them are smaller than 9 mm while about 10-20% are larger macrocysts. While the smaller cysts mostly disappear within 6 months the larger ones appear to be more persistent.

Although most cases of ovarian cysts involve monitoring, some cases require surgery. This may involve removing the cyst, or one or both ovaries. Technique is typically laparoscopic, unless the cyst is particularly large, or if pre-operative imaging suggests malignancy or complex anatomy. In certain situations, the cyst is entirely removed, while with cysts with low recurrence risk, younger patients, or which are in anatomically eloquent areas of the pelvis, they can be drained. Features that may indicate the need for surgery include:

- Persistent complex ovarian cysts

- Persistent cysts that are causing symptoms

- Complex ovarian cysts larger than 5 cm

- Simple ovarian cysts larger 10 cm or larger than 5 cm in postmenopausal patients

- Women who are menopausal or perimenopausal

Alcohol consumption does not appear to be related to ovarian cancer. Other factors that have been investigated, such as smoking, low levels of vitamin D in the blood, presence of inclusion ovarian cysts, and infection with human papilloma virus (the cause of some cases of cervical cancer), have been disproven as risk factors for ovarian cancer. The carcinogenicity of perineal talc is controversial, because it can act as an irritant if it travels through the reproductive tract to the ovaries. Case-control studies have shown that use of perineal talc does increase the risk of ovarian cancer, but using talc more often does not create a greater risk. Use of talc elsewhere on the body is unrelated to ovarian cancer. Sitting regularly for prolonged periods is associated with higher mortality from epithelial ovarian cancer. The risk is not negated by regular exercise, though it is lowered.

Increased age (up to the 70s) is a risk factor for epithelial ovarian cancer because more mutations in cells can accumulate and eventually cause cancer. Those over 80 are at slightly lower risk.

Smoking tobacco is associated with a higher risk of mucinous ovarian cancer; after smoking cessation, the risk eventually returns to normal.A diet high in animal fats may be associated with ovarian cancer, but the connection is unclear. Diet seems to play a very small role, if any, in ovarian cancer risk.

Higher levels of C-reactive protein are associated with a higher risk of developing ovarian cancer.

Industrialized nations, with the exception of Japan, have high rates of epithelial ovarian cancer, which may be due to diet in those countries. Caucasian are at a 30–40% higher risk for ovarian cancer when compared to Black and Hispanic people, likely due to socioeconomic factors; white women tend to have fewer children and different rates of gynecologic surgeries that affect risk for ovarian cancer.

Cohort studies have found a correlation between dairy consumption and ovarian cancer, but case-control studies do not show this correlation. There is mixed evidence regarding the effect of red meat and processed meat in ovarian cancer.

Tentative evidence suggests that talc, pesticides, and herbicides increase the risk of ovarian cancer. The American Cancer Society notes that as of now, no study has been able to accurately link any single chemical in the environment, or in the human diet, directly to mutations that cause ovarian cancer.

A peritoneal inclusion cyst is a cyst-like structure that appears in the pelvis due to non neoplastic reactive mesothelial proliferation, often as a consequence of prior episodes of pelvic inflammation, as can occur in pelvic inflammatory disease. It has the potential to mimic ovarian cysts, hydrosalpinx or even malignancy, due to its nonspecific anechoic appearance.

Definitive causes of ureterocele have not been found. While the abnormal growth occurs within the uterus, it has not been substantiated that genetics are to blame.

Many other complications arise from ureteroceles. Redundant collection systems are usually smaller in diameter than single, and predispose the patient to impassable kidney stones. The effective "bladder within a bladder" compounds this problem by increasing the collision of uric acid particles, the process by which uric acid stones are formed. Ureterocele is also associated with poor kidney function. It can cause frequent blockage of the ureter leading to serious kidney damage. In other cases, a small, upper portion of the kidney is congenitally non-functional. Though often benign, this problem can necessitate the removal of non-functioning parts.

In medicine, Meigs' syndrome, also Meigs syndrome or Demons-Meigs syndrome, is the triad of ascites, pleural effusion, and benign ovarian tumor (ovarian fibroma, fibrothecoma, Brenner tumour, and occasionally granulosa cell tumour). Meigs' syndrome resolves after the resection of the tumor. Because the transdiaphragmatic lymphatic channels are larger in diameter on the right, the pleural effusion is classically on the right side. The causes of the ascites and pleural effusion are poorly understood. Atypical Meigs' syndrome, characterized by a benign pelvic mass with right-sided pleural effusion but without ascites, can also occur. As in Meigs syndrome, pleural effusion resolves after removal of the pelvic mass.

Meigs syndrome may mimic other conditions, since it is tumor arising from ovaries, pathology of any organs present in the abdomen may show a similar set of symptoms. Various gynecological disorders of the uterus such as endometrial tumor, sarcoma, leiomyoma (pseudo-Meigs syndrome); fallopian tube disorders such as hydrosalpinx, granulomatous salpingitis, fallopian tube malignancy; ovarian disorders such as serous, mucinous, endometrioid, or clear cell carcinoma, Brenner tumor, granulosa cell tumor, stromal tumor, dysgerminoma, fibroma, or metastatic tumor to the ovary.

Meigs syndrome is characterized by the presence of a benign solid ovarian tumor associated with ascites and right hydrothorax that disappear after tumor removal. Non-gynecological manifestations include:

ascites, portal vein obstruction, inferior vena cava obstruction, hypoproteinaemia, thoracic duct obstruction, tuberculosis, amyloidosis, pancreatitis, ovarian hyperstimulation, pleural effusion transudative, congestive heart failure, metastatic tumors to the peritoneal surfaces, collagen-vascular disease, and cirrhosis of the liver.

These entities must be clinically excluded.

Clinical condition characterized by ovarian mass, ascites, and right-sided pleural effusion.Ovarian malignancy and the

other causes (see “Differential Diagnosis”) of pelvic mass, ascites, and pleural effusion to be considered, History of early satiety,

weight loss with increased abdominal girth, bloating, intermittent abdominal pain, dyspnea, nonproductive cough may help in differentiating potential local factor causing such symptoms.