Hormones regulate many important bodily functions. For instance, The Merck Manuals Online Medical Library reports that the delicate interaction between estrogen and progesterone, along with the pituitary and hypothalamic hormones, is essential for a woman's ovulation and consequently fertility. However, a hormonal imbalance may affect the reproductive capacity of males and females alike. Also, prolonged increase of circulating levels of certain hormones may increase the risk of developing certain types of cancers.
Female Infertility
Female fertility is largely dependent, among other things, on ovulation. According to the Merck Manuals Online Medical Library, in order for ovulation to occur, the intricate interaction between the luteinizing hormone and the follicle stimulating hormones with estrogen and progesterone needs to be fully operational. Any dysfunction can cause failure of release of the egg; and with no ovulation, the female is infertile and no pregnancy can occur. MayoClinic.com states that failure of ovulation due to a hormonal imbalance accounts for almost one quarter of infertile females. Another hormonal imbalance that could cause infertility is the "luteal phase defect." This is a defect brought upon by a lack of sufficient progesterone in the body after ovulation. Progesterone is responsible for the preparation of the uterine lining for implantation of the fertilized egg. It is also needed for the support of the early developing embryo until the placenta is formed.
Male Infertility
As outlined by the Merck Manuals Medical Online Library, hormonal imbalances can also cause male infertility. Certain hormonal disorders interfere with the production of sperm causing a reduced number of sperm in the semen. The hormonal conditions that may cause an inhibition of sperm production leading the infertility include imbalances in the thyroid hormones, pituitary gland hormones, and reduction of levels of testosterone. It is also worth noting that the intake of anabolic steroids for purposes of bodybuilding may cause infertility because anabolic steroids cause reduction in the levels of pituitary hormones responsible for stimulating spermatogenesis, or sperm production.
Increased Risk of Cancer
Some hormonal imbalances predispose a person to an increased risk of cancer. For example, the Cancer Research Institute in the UK reports that a definite link has been established between insulin levels and cancers of the pancreas, kidneys, intestines and the womb. Also, MayoClinic.com states that elevated levels of estrogen have been proven to be a significant risk factor for the development of the cancer of the lining of the uterus, medically known as endometrial carcinoma. All conditions that cause an elevated level of estrogen, with not enough progesterone, stimulates the lining of the uterus to proliferate and predisposing the endometrium for malignant transformation.
