Normally, the most dominant hormones in the life of female human beings are the estrogen and progesterone that control the reproductive system.Naturally, the presence of these hormones in the body system of human beings should be balanced. A decrease or increase in one of the two hormones usually creates problems and this is why we have seen development of health conditions such as the uterine fibroids, among other problems that affect the reproductive system of women.The presence of too much estrogen in a person’s body system relative to progesterone creates a state of estrogen dominance.Usually in the development of females right from the stage of puberty to menopause, a woman’s body is designed to have estrogen and progesterone work together to regulate the menstruation cycle.The bulk of estrogen is released into a woman’s blood circulation during the first half of her monthly cycle. Estrogen works to build the lining of a woman’s uterus to prepare it for implantation of a fertilised egg should fertilisation occur.The bulk of progesterone is released into a woman’s blood stream during the second half of a healthy monthly cycle. During this time, progesterone acts to maintain the rich lining of the uterus that estrogen helped to build up during the first two weeks of her cycle.If a fertilised egg successfully implants into the uterine wall or, for example, if a woman becomes pregnant, her body must continue to produce a large amount of progesterone on a continuous basis to maintain a thick and well vascularised uterine wall throughout the course of pregnancy. The control of progesterone production is done by the placenta in this case.If there is no implantation or pregnancy, a woman’s body stops producing large amounts of progesterone, which results in sloughing off and elimination of the thickened uterine lining, also known as a woman’s monthly flow.This cycle repeats itself about once every month until a woman experiences menopause, with estrogen dominating the first half of each cycle, and progesterone dominating the second half.However, some women or young girls do possess too much estrogen or very low progesterone in their body systems.Now, the origin of fibroids can be explained by the fact that if estrogen hormone is too much in the body and the excessive thickening continues. It results in the accumulation of abnormal cells that forms a relatively less aggressive thick mass  in the uterus or outer lining of the uterus.This kind of over-growth in the uterus or its anatomical linings is the basis of uterine fibroids formation. There are factors that can lead to estrogen dominance.One of the most important factors to mention here is the life time or chronic stress that might be exposed to your health.When a person experiences stress for along time, there is a high likelihood to create a hormonal imbalance in her body system with remarkable decline of progesterone. We experience lowering of progesterone as some or most of it is transformed into stress hormone cortisol.Stress predominantly brings about low level of progesterone in the blood system and this creates an imbalance of estrogen-progesterone hormone quantity in blood. Stress largely affects the reproductive system of females and perhaps this is why we have seen majority of women dislike stressful lifestyle or unstable environment around them.Another factor that can bring about the imbalance is the over-weight or fatty cells in the body. Fat cells are one of the estrogen producers in the body and the fatter a person becomes, the more likelihood of estrogen production. This explains why regular exercise as a lifestyle weight control measure is highly recommended. Other areas of estrogen production include the testis in men and ovaries in females. Adrenal glands are also highly implicated in estrogen production.Another factor that can increase estrogen amount in the body is the continued use of artificially manipulated estrogen. Artificial estrogen is seen in most of man-made reproductive health control materials such as condom spermicidal, birth control pills, among others.Dr Joseph Kamugisha is a resident oncologist in Jerusalem, Israel