The uterus, sometimes called the womb, is a muscular organ located at the very top of the vagina. The cervix, which is really the bottom part of the uterus, connects the vagina and the uterus. During pregnancy the baby grows within the lining of the uterus. The uterus grows from it's normal size of a pear to the size of a watermelon during pregnancy. When labor starts, contractions within the uterine muscle fibers help the cervix dilate and the baby deliver. When not pregnant, the uterus goes through a monthly menstrual cycle that depends on hormones coming from the ovaries. These hormones mostly affect the lining of the uterus. The lining swells during the first few weeks of the cycle, then slowly dies off during the last few weeks. This causes the lining to "slough off" which creates menstrual flow. Since this lining is sensitive to hormones, any abnormality of these hormones can cause irregular bleeding. Furthermore, common, non-cancerous, tumors called fibroids can grow within the muscular layer of the uterus and cause symptoms like pain, pressure, heavy and irregular bleeding, and constipation. For a more thorough discussion of fibroids, please click here. Other conditions, like endometrial polyps (tiny growths within the lining of the uterus), pre-cancer, and even uterine cancer can cause heavy and abnromal bleeding.
Doctors evaluating abnormal bleeding or an enlarged uterus may perform a number of tests. These might include ultrasound, where sound waves are used to look at the uterus, hysteroscopy, where a lighted tube is inserted into the uterus to look at the uterine lining, or laparoscopy, where a lighted tube is inserted through the belly button (with the patient under anesthesia) to look at the uterus from the inside.
Click on the description below to see the JPG photo.
Normal uterus as seen by laparoscopy
The uterus and uterine cavity as seen with ultrasound.
Uterine fibroids as seen through a laparoscope.
Massive uterine fibroids.