What is estrogen?

Estrogen is known as the "female" hormone, while testosterone is more "male" hormone. Although identified with a particular sex, two hormones occur in women and men. The difference is in the amount of - women have more estrogen and men - more testosterone. Estrogen is responsible for sexual development in women - it regulates the menstrual cycle and affects the whole reproductive system.
What is the role of estrogen level and what is estrogen dominance?
Estrogen and progesterone are the two main female hormones. During the normal menstrual cycle, they take turns in managing the processes of maturation and release of the egg and prepare the uterus for possible pregnancy. Estrogen dominates in the first half of the cycle, with peaks at ovulation and during the second half of the cycle, progesterone rises. If no pregnancy should menstruation and the whole cycle begins again.

When estrogen, progesterone and testosterone do their job, they work well together. How much of each hormone is produced at any one time is determined by a complex feedback system between the brain, ovaries and adrenal glands. Stress, diet and lifestyle affect this system of connections and thus give a direct impact on the hormonal balance.
What are the symptoms of high estrogen?
When the levels of estrogen and testosterone in the body are out of sync, it can cause the appearance of certain symptoms. These may include: bloating; swelling and soreness in the chest; decreased sex drive; irregular menstrual cycle; headache; mood swings; fibrocystic breast formations; weight gain; hair loss; cold extremities; fatigue or lack of energy; difficulty with memory; trouble sleeping; elevated symptoms of premenstrual syndrome.
What are the causes estrogen dominance?