Estrogen levels are constantly fluctuating throughout a woman's reproductive life. On a monthly basis, menstruation guides its consistent fluctuation in preparation to nourish another human being. This occurs up until menopause when she has her last menstrual cycle.
However, maintaining normal estrogen levels is important not only for reproductive health, but a number of important bodily functions. Therefore, an estrogen imbalance during any stage in life can wreak havoc on body harmony.
Continue reading to learn more about healthy estrogen levels and its importance, including the negative effects of an estrogen imbalance.
Ranges of Normal Estrogen Levels
Average Daily Estrogen Levels
This table shows the average daily estrogen levels for a woman at different times during and after her reproductive years. Measurements are taken from blood serum - except for pregnancy's values, which are from plasma – and given in parts pg/mL (picograms/milliliter) of estradiol. Keep in mind that measured levels of estradiol can vary depending on the type of test implemented.
A woman of reproductive age will have estradiol levels ranging from 30 – 400 pg/mL. Estrogen rises during the follicular phase, peaks at ovulation, and then drops during the luteal phase, only for the cycle to repeat again.
In pregnant women, blood plasma estradiol levels can range between 5,500 – 30,000 pg/mL. Research shows that during this time, estradiol levels increase 50- to 180-fold. However, the main estrogen produced by the placenta is actually estriol, which will constitute 60 – 70% of the total estrogens generated.
Estradiol levels will usually hover below 30 pg/mL. After reproductive years have ended, estrone is the main estrogen created; therefore, its level should be taken into consideration as well. With HRT or other treatments, total estrogen levels can rise substantially.
Importance of Normal Estrogen Levels
The effects of maintaining healthy estrogen levels in women are felt beginning with menarche - the beginning of menstruation - and extending into postmenopause. The following are several examples of the hormone's actions.
- Collaborates with other hormones to initiate the onset of menstruation
- Stimulates the development of breasts
- Matures the reproductive tract
- Prepares breast glands for future milk production
- Maintains thickness and lubrication of vaginal lining and mucous membranes
- Causes growth and changes in mother's reproductive system and metabolism
- Helps stimulate the secretion of prolactin
- Prompts uterine contractions when baby is at term
After the Menstrual Years
- Regulates bone mass and strength
- Preserves skin tension and strength of pelvic muscles
- Enhances urethral resistance
- Possibly delays memory loss
- Maintains body temperature
Keep in mind that even though many of the aforementioned effects are sectioned into the varying life stages, they are interchangeable, where applicable.
Read more about estrogen's role and effects for a better understanding of how the hormone influences one's well-being.
What Happens When Estrogen Levels are High?
Because levels of estrogen fluctuate on a daily basis, current estrogen levels are widely based on age, current stage of the menstrual cycle, and external factors, such as stress.
Nevertheless, no matter the variation, an estrogen imbalance in which levels are abnormally high or low can cause a variety of negative effects.
When in adulthood, estrogen imbalance - more specifically, estrogen dominance - can provoke monthly premenstrual syndrome (PMS) symptoms, including breast tenderness, acne, joint pain, migraines, mood swings, bloating, and more. Moreover, excessive estrogen levels can bring about a variety of health conditions the longer the imbalance prevails. These conditions include polycystic ovarian syndrome (PCOS), endometriosis, and uterine fibroids.
Estrogen naturally increases during pregnancy in order to initiate changes within the mother's uterus, cervix, vagina, and breasts as well as within other body systems. However, the sudden influx in estrogen levels may lead to short-term symptoms, like cramps, fatigue, and headaches.
After menopause, excessive estrogen levels manifest through symptoms such as hot flashes, weight gain, memory lapses, and irregular menstrual periods, among others. If left untreated, the underlying hormonal imbalance can eventually lead to life-threatening conditions such as breast cancer, uterine cancer, and ovarian cancer.
Read more information about high estrogen levels, including warning signs and symptoms.
What Happens When Estrogen Levels are Low?
First off, an estrogen imbalance during initiation of menstrual years can cause delayed puberty. Signs of delayed puberty include lack of breast development by the age of 13 as well as amenorrhea - lack of periods - following breast development. Furthermore, continually low estrogen levels may lead to recurring urinary tract infections (UTIs), vaginal irritation, hair loss, and further symptoms.
Having insufficient estrogen levels during the follicular phase may lead to anovulatory menstrual cycles in which there is no ovulation. As such, it is impossible to naturally conceive. Additionally, because estrogen helps build up the uterine lining in preparation for egg implantation, an estrogen imbalance can cause a miscarriage.
When fertile years end, and estrogen levels dip below normal, the hormonal imbalance can lead to symptoms such as hot flashes, vaginal dryness, incontinence, weaker skin elasticity, and more. If left untreated, low estrogen levels can lead to more serious health conditions, such as osteoporosis, heart disease, and vaginal atrophy, among others.
Accordingly, to begin to clear up any ambiguities in regards to hormonal balance and overall health and well-being, continue reading to learn more about low estrogen levels and its causes.
- Bader, M. (Ed.). (2008). Cardiovascular Hormone Systems: From Molecular Mechanisms to Novel Therapeutics. New Jersey: Wiley-Blackwell. Available from Google Books.
- Blakeway, J. (2016). Addressing Estrogen Dominance in Perimenopausal Women Using TCM. Retrieved August 14, 2017, from http://www.pacificcollege.edu/news/blog/2016/01/14/addressing-estrogen-dominance-perimenopausal-women-using-tcm
- Breastcancer.org. (2016). Tests to Determine Menopausal Status. Retrieved August 9, 2017, from http://www.breastcancer.org/tips/menopausal/types/determine-status
- Carpenter, S. (2001). Does estrogen protect memory? American Psychological Association, 32(1), 52. Retrieved August 11, 2017, from http://www.apa.org/monitor/jan01/estrogen.aspx
- Eagle, S. et al. (2009). The Professional Medical Assistant: An Integrative, Teamwork-Based Approach. Pennsylvania: F.A. Davis Company. Available from Google Books.
- Henderson, V.W. (2009). Cognitive Changes After Menopause: Influence of Estrogen. Clinical Obstetrics and Gynecology, 51(3), 618-626. doi: 10.1097/GRF.0b013e318180ba10
- Imai, Y. et al. (2009). Estrogens maintain bone mass by regulating expression of genes controlling function and life span in mature osteoclasts. Annals of the New York Academy of Sciences, 1173 Suppl 1, E31-9. Retrieved August 11, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/19751412
- Luthje, P et al. (2013). Estrogen Supports Urothelial Defense Mechanisms. Science Translational Medicine, 5(190), 190ra80. doi: 10.1126/scitranslmed.3005574
- The National Infertility Association. (n.d.). Common Causes of Miscarriage. Retrieved August 11, 2017, from http://www.resolve.org/about-infertility/medical-conditions/common-causes-of-miscarriage.html
- National Women's Health Resource Center, Inc. (2017). Estrogen | Atherosclerosis. Retrieved August 11, 2017, from http://www.healthywomen.org/condition/estrogen | http://www.healthywomen.org/condition/atherosclerosis
- Norris, D.O. (2007). Vertebrate Endocrinology: Fourth Edition. Massachusetts: Elsevier. Available from Google Books.
- The North American Menopause Society. (2010). Changes in Hormone Levels. Retrieved August 9, 2017, from https://www.menopause.org/for-women/sexual-health-menopause-online/changes-at-midlife/changes-in-hormone-levels
- PubChem: Open Chemistry Database. (n.d.). Estriol. Retrieved August 14, 2017, from https://pubchem.ncbi.nlm.nih.gov/compound/estriol#section=Top
- Samuels, M. & Samuels, N. (1996). The New Well Pregnancy Book. New York: Fireside. Available from Google Books.
- Stevenson, S. & Thornton, J. (2007). Effect of estrogens on skin aging and the potential role of SERMs. Clinical Interventions in Aging, 2(3), 283-297. Retrieved August 11, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2685269/
- Tulane University. (n.d.). The Hormones: Estrogens. Retrieved August 9, 2017, from http://e.hormone.tulane.edu/learning/estrogens.html
- University of Rochester Medical Center. (2017). Estrogen's Effects on the Female Body | Health Encyclopedia: Estradiol (Blood). Retrieved August 14, 2017, from https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=85&ContentID=P00559 | https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=estradiol
- U.S. Department of Health and Human Services. (n.d.). Premenstrual syndrome. Retrieved August 14, 2017, from https://www.womenshealth.gov/a-z-topics/premenstrual-syndrome
- Weber, M.A. (2015). Local Oestrogen for Pelvic Floor Disorders: A Systematic Review. PLOS ONE, 10(9), e0136265. doi: 10.1371/journal.pone.0136265
- Women in Balance Institute. (n.d.). About Hormone Imbalance. Retrieved August 9, 2017, from https://womeninbalance.org/about-hormone-imbalance/