To better understand dysfunctional uterine bleeding, it helps to understand the anatomy of the uterus and cervix.
The female reproductive organs include the vagina, cervix, uterus, fallopian tubes and ovaries. The lining of the uterus is called the endometrium.
Before ovulation, the endometrium grows and becomes thick: the endometrial tissue and blood vessels support the fertilized egg when it enters the uterus.
During ovulation, an egg is released from one of the ovaries and enters the fallopian tube. If the egg is fertilized as it passes through the fallopian tube, it attaches to the endometrium on the inside of the uterus. The endometrium continues to support the fertilized egg as it grows.
If the egg is not fertilized, the egg does not attach to the endometrium and the endometrium breaks down. The uterus sheds the endometrium, which causes the bleeding associated with the menstrual period.
- Abbott J, Hawe J, Hunter D, Garry R. A double-blind randomized trial comparing the Cavaterm and the NovaSure endometrial ablation systems for the treatment of dysfunctional uterine bleeding. Fertil Steril. 2003 Jul;80(1):203-8. 
- Agarwal N, Kriplani A. Medical management of dysfunctional uterine bleeding. Int J Gynaecol Obstet. 2001 Nov;75(2):199-201. 
- Bourdrez P, Bongers MY, Mol BW. Treatment of dysfunctional uterine bleeding: patient preferences for endometrial ablation, a levonorgestrel-releasing intrauterine device, or hysterectomy. Fertil Steril. 2004 Jul;82(1):160-6. 
- Munro MG. Dysfunctional uterine bleeding: advances in diagnosis and treatment. Curr Opin Obstet Gynecol. 2001 Oct;13(5):475-89.