there are two major reasons for very prolonged/heavy periods: hormonal and what i call "structural. " "structural" means when excessive bleeding is due to actual problems within the cavity or walls of the uterus. some examples of this would include fibroids of the uterus endometriosis of the muscular wall of the uterus ("adenomyosis") infections of the lining of the uterus polyps of the uterine lining or even uterine cancer. hormonal causes are usually linked to missed or erratic ovulations. as you may know in a normal cycle estrogen is produced all month. estrogen is responsible for building up the lining of your uterus so you have something to shed each month. in a normal cycle progesterone production increases following ovulation. progesterone "stabilizes" the uterine lining in preparation for a possible implantation of a new pregnancy. if you are not pregnant that month the levels of estrogen and progesterone fall triggering the release of the uterine lining—your period. so if you do not ovulate the estrogen build up of the lining continues but without the usual ovulation associated progesterone. thus the hormone levels don't decline and the lining stays up inside the uterus—your missed/late period. alternatively the lining can begin to shed under its own weight producing prolonged bleeding. another way inadequate progesterone production from missed ovulations can create too heavy a flow is as follows. simply stated if the uterine lining is like grass or lawn estrogen is like the fertilizer (causes proliferation and a thickening of the lining ) and progesterone is like the lawnmower (keeps the lining thin by three different mechanisms). this is why depoprovera (high dose synthetic progesterone) brings about a thin lining and why birth control pills (relatively progesterone dominant) bring about shorter lighter periods. it is also why women who miss ovulations (no progesterone produced) are at a greater risk for too thick lining. causes for not ovulating are multifold: thyroid problems pituitary problems ovarian cysts physical stressors (e. g. sudden increases in exercise crash dieting) emotional stressors (problems with spouses kids job money) increased body weight anorexia rotating shifts at work etc. if they are sending you for an ultrasound that can accomplish two things. an ultrasound should be able to visualize fibroids of the uterus or suggest polyps. an ultrasound can also measure the thickness of your uterine lining. a very thick lining can suggest a hormonal cause like missed ovulations. an ultrasound should be able to visualize an ovarian cyst if that was the cause of missed ovulations. lastly . as we age ovulations tend to decrease--or if they occur the amount of progesterone produced may be less. structural causes such as fibroids or polyps also tend to be more common as we age. hopefully you will get a more "for sure" answer after your ultrasound.
why do i have heavy bleeding for 2-3 weeks when i get my period? my doctor is supposed to send me for an ultrasound.