Estrogen is the collective name given to a number of sex hormones. Although estrogen is produced in both the male and female bodies, it is most often referred to as one of the female hormones. If estrogen levels are not in the proper balance, a variety of effects on the body is possible. Effects of low estrogen include menstrual irregularity, high cholesterol levels and osteoporosis.
Surges of estrogen during the menstrual cycle affect the ovaries and uterus, causing ovulation and the thickening of the uterine lining in preparation for receiving a fertilized egg. A decrease in estrogen levels toward the end of the cycle causes the uterine lining to shed, a process known as the menstrual period. If a woman suffers from low estrogen levels, her ovaries and uterus may not respond properly, leading to an absence of ovulation and possibly menstruation as well. For this reason, women planning a pregnancy may find that estrogen imbalance leads to fertility issues. Older women may have an estrogen deficiency as they begin menopause, the cessation of menstruation.
Low estrogen also affects the liver and its production of cholesterol. The proper estrogen balance influences the liver to produce more high-density lipoprotein (HDL) and less low-density lipoprotein (LDL). Too much LDL cholesterol in the blood may lead to the formation of plaque in the body's major arteries, as LDL can stick to the walls of these vessels. HDL, often called the good cholesterol, does not stick to the arteries and may help prevent plaque from forming at all.
As women age, they become more prone to osteoporosis, a condition characterized by brittle bones. Typically, estrogen works with Vitamin D and calcium to help keep bones strong, healthy and resistant to breakage. Low estrogen levels, such as those in menopausal and postmenopausal women, can lead to a loss of up to 20 percent of total bone mass. This loss of mass weakens the bones, making them more susceptible to fracture. Broken bones do not heal as easily in older patients, making such an injury even more dangerous.
Low estrogen levels may be treated with medication. Estrogen supplements may be given orally or via patches, gels or creams. This treatment, also known as hormone replacement therapy, is not appropriate for all patients. Some women who should not undergo hormone replacement therapy for low estrogen include those with a history of blood clots or heart disease, as well as those who have had breast cancer.