context: Endometriosis is a common and painful disease that affects about 5.5 million women in North America and is one of the top three causes of infertility in women. During a normal menstrual cycle, the lining of your uterus -- called the endometrium -- begins to thicken in preparation for becoming pregnant. If you don't become pregnant that month, your body sheds the endometrium during menstruation and the process starts over. In endometriosis, for reasons that researchers don't entirely understand, tissue very similar to the endometrium begins to grow outside the uterus in various places that it shouldn't. It can appear in or on the ovaries, the fallopian tubes, the various structures that support the uterus, and the lining of the pelvic cavity. Sometimes, it's found in other places as well, including the cervix, vagina, rectum, bladder, bowel, and elsewhere. The problem is that this tissue behaves like normal endometrial tissue -- it builds up and breaks down with your menstrual cycle -- but it can't be shed like normal endometrial tissue during your period. As a result, the rogue tissue causes irritation and inflammation. This buildup of tissue can prevent the eggs from getting out of the ovaries or being fertilized by sperm. It can also scar and block the fallopian tubes, preventing the egg and sperm from meeting. In addition to fertility problems, some common signs and symptoms of endometriosis include: Pelvic pain Painful intercourse Painful urination Painful bowel movements Severe abdominal pain Lower back pain Heavy periods or spotting between periods Fatigue Some women with endometriosis do not have symptoms. Most women who have endometriosis can conceive normally. But if you're having problems getting pregnant, endometriosis may be the cause. To find out, your doctor may suggest a laparoscopy. In this procedure, a surgeon inserts a small camera through a tube into your abdomen to check for abnormal endometrial tissue. The surgeon might want to confirm the diagnosis with a biopsy. If you've been diagnosed with endometriosis, you have several treatment options, depending on the severity of the disease. Medication, either alone or in combination with surgery, can often decrease inflammation and reduce pain. If you and your doctor opt for surgery, the surgeon can attempt to remove as much of the diseased tissue as possible. In some women, surgery significantly improves their chances of getting pregnant. You should know, however, that pregnancy rates tend to be lower for women with severe endometriosis. Because some women with endometriosis have ovulation problems, another treatment option is the use of fertility drugs such as Clomid to induce ovulation. Injectable hormones also may be prescribed for the same reason. Once you begin to successfully ovulate, your doctor may suggest trying artificial insemination, in which sperm is inserted directly into your uterus. Keep in mind that some standard treatments for endometriosis can either prevent pregnancy or, in the case of the hormone Danocrine, cause serious birth defects. Make sure your doctor knows that you are trying to conceive if you're being treated for endometriosis. Problems with the fallopian tubes also account for a significant percentage of infertility cases. Sometimes, the tubes may be blocked or they may be scarred as a result of disease or infection. When an egg is released from one of the ovaries, it travels through one of the fallopian tubes, which are narrow ducts that connect the ovaries to the uterus. Normally, the egg will join with the sperm in the fallopian tubes during conception and the now-fertilized egg will continue on to the uterus. However, the fallopian tubes are extremely fragile. If they are blocked, there's no way for the egg to become fertilized by the sperm. The fallopian tubes can be damaged by diseases such as endometriosis, pelvic inflammatory disease, infections and sexually transmitted diseases. To determine whether your fallopian tubes are blocked, your doctor may suggest a laparoscopy or a hysterosalpingogram ( HSG). In an HSG test, liquid dye is inserted by catheter through the vagina (cervix) into the uterus. Then, X-rays are taken to see if there is a blockage or if the dye flows freely into the abdomen. Another method of HSG uses saline and air rather than dye and ultrasound instead of X-ray. If you have problems with your fallopian tubes, your doctor may recommend surgery to correct the damage or unblock the tubes. If you're ovulating normally, your doctor might also consider assisted reproduction techniques that bypass the fallopian tubes entirely. These can include intracytoplasmic sperm injection ( ICSI), artificial insemination directly into the uterus ( IUI) and in vitro fertilization ( IVF).