Dysfunctional uterine bleeding (DUB):

Defined as abnormal uterine bleeding for which no apparent reason can be found.  The diagnosis should therefor only be made if all other causes of abnormal uterine bleeding have been excluded.

Divided into: 

A)  An-ovulatory DUB due to:

1) Excessive estrogen stimulation of the endometrium
2) Under stimulation of the endometrium, for example inadequate or absent stimulation

B) Ovulatory DUB due to:

 1)   Poor formation and/or function of the corpus luteum.
 2)   Incomplete and/or slow degeneration of the corpus luteum. 

A thorough history taking, clinical examination and special examinations like ultrasound, will help the diagnosis and treatment planning of DUB.