Headaches can be caused by stress, neck strain, eye fatigue, vascular disease, brain tumors, and many other problems. With menstrual irregularity, as with headaches, the irregularity is not specifically due to a particular problem in the womb, but may be the end result of many different diseases. Firstly, the most obvious organ involved in the menstrual cycle is the uterus. This cyclic shedding of the uterine lining is controlled by a cyclic variation in the levels of two types of hormones known as estrogens and progesterone are produced by the ovaries. The structure in the ovaries containing the maturing egg and the follicle produces estrogen during the first half of the menstrual cycle.
Progesterone causes changes in the endometrial lining which prepare it for pregnancy.
If pregnancy does not occur, the progesterone levels decrease, and the endometrium is shed. This action results in a menstrual flow approximately on the 28th day of the menstrual cycle. Disturbances of follicular development will therefore result in a disturbed menstrual cycle. However, in the absence of any of the above causes, irregular bleeding from the uterus is typically caused by a disturbed cyclic hormone production by the ovaries. A pelvic examination and a Pap smear can detect some of these problems.