All About Estradiol Levels – The Main Estrogenic Hormone
The Biomarker Handbook is a curated series that seeks to provide readers with insights on each biomarker we cover in our blood test packages and its relation to our body.
Estrogens are a group of steroids that are involved in the development, regulation and function of female secondary sexual characteristics and reproductive organs, while also playing a role in menstrual cycle regulation and pregnancy maintenance.
Even though these have been considered to be exclusively female hormones, they are also involved in bone metabolism and growth in both males and females.
There are three types of estrogens we can test for, but the commonest available test measures estradiol (E2):
– Estrone (E1): it is the main type of estrogen that can be found in men and post-menopausal women.
– Estradiol (E2): it is mostly produced in the ovaries of pre-menopausal women and the testicles of men. Estradiol is considered to be the most potent estrogen and the one with the higher concentration in non-pregnant, pre-menopausal women.
– Estriol (E3): it is produced by the placenta, which makes it the principal pregnancy estrogen. Estriol does not play a significant function in either men or non-pregnant women.
The main estrogenic hormone is considered to be estradiol because it is the hormone that can be found in greater quantities in non-pregnant pre-menopausal women; and its the hormone that its mainly involved in the development of female secondary sexual characteristics (breast, pubic hair, etc.) and menstrual cycle maintenance.
Why is it Important to Keep Track of Estradiol Levels?
In women, measurement of estradiol levels is an essential part of the reproductive function evaluation. Estradiol testing can be ordered by your doctor for many reasons:
– Assessment of oligomenorrhea (infrequent menstruation), amenorrhea (no menstruation), or hypogonadism (reduced ovarian function, delayed puberty).
– Investigate abnormal vaginal bleeding.
– Evaluation of ovarian health and function for assisted reproduction protocols, such as in-vitro fertilisation.
– To help diagnose the cause of precocious or delayed puberty.
– To monitor estrogen replacement therapy.
– To monitor anti-estrogen therapy.
– Diagnose possible disorders of sex steroid metabolism.
– Detect estrogen-producing tumors
– As part of the assessment of bone mineral density measurement in the fracture risk evaluation.
In males, measurement of estradiol levels can be performed in situations such as:
– Assessment of feminisation disorders, including gynecomastia (enlarged breasts in men)
– To help diagnose estrogen-producing cancers.
What are Normal Estradiol Levels?
Normal estradiol results depend upon the age and sex of the individual being tested. Regarding women, it also depends upon the menstrual cycle or if they are pregnant.
- For female children:
– Average age of 7.1 years (Tanner I stage of sexual development): Undetectable to 20 pg/mL
– Average age of 10.5 years (Tanner II stage of sexual development): Undetectable to 24 pg/mL
– Average age of 11.6 years (Tanner III stage of sexual development): Undetectable to 60 pg/mL
– Average age of 12.3 years (Tanner IV stage of sexual development): 15-85 pg/mL
– Average age of 14.5 years (Tanner V stage of sexual development): 15-350 pg/mL
- For adults:
– Males: 10-40 pg/mL
– Premenopausal women: 15-350 pg/mL (changes markedly during different phases of menstrual cycle)
– Postmenopausal women: <10 pg/mL
What are the Signs and Symptoms of an Estradiol Imbalance?
An imbalance in estradiol levels can have manifestations as follows:
– Early or late sex organ development
– Irregular and abnormal menstruation
– Abnormal vaginal bleeding
– Lack of menstrual periods
– Breast swelling and tenderness
– Headaches (premenstrually)
– Mood swings (often irritability and depression)
– Reduced sex drive
– Signs of feminisation, such as gynecomastia (enlarged breasts)
When to See the Doctor
You should visit your doctor if you experience any of the signs or symptoms mentioned above.
Other circumstances where you should get tested to know your estradiol levels include:
– If you are undergoing infertility treatment
– If you are having estrogen replacement therapy for menopause symptoms
What can Cause Abnormal Estradiol Levels?
Usually, estrogen levels are not used on its own to assess a condition or disorder, but rather in conjunction with other tests. Estradiol (E2) values must be corroborated with a woman’s menstrual cycle or pregnancy status.
- Heightened levels of estradiol can be due to:
In females: early puberty, hyperthyroidism (overactive thyroid gland), tumours of the ovary, tumours of the adrenal glands, or hormone pills. Certain foods are high in estrogens (diary, soy products, certain fruits and vegetables, olive oil, sesame seeds).
In males: gynecomastia (enlarged breasts), cirrhosis, delayed puberty, hyperthyroidism, testicular cancer, or tumors of the adrenal glands.
- Decreased levels of estradiol in women are seen in:
– Turner syndrome (a genetic condition in women caused by a missing or abnormal X chromosome).
– After menopause
– Dysfunction of the ovaries (hypogonadism)
– Eating disorders, like anorexia
– PCOS (polycystic ovarian syndrome)
– Extreme endurance exercise
Consequences of Having Abnormal Estradiol Levels?
Prolonged time with either decreased or heightened estradiol levels can cause health issues like infertility, osteoporosis, thrombosis, strokes, diabetes, high blood pressure or estrogen-dependent cancer such as endometrial cancer.
Can Estradiol Levels Be Normalised?
The first step is to diagnose and treat the cause of the estrogen levels imbalance. If that’s not possible, several preparations can be used to treat abnormal estrogen levels. These include using estradiol as hormone replacement therapy (HRT), infertility treatment, or as a contraceptive in birth pills when its levels are too low. Or decreasing its levels by using certain medications that prevent estradiol production, block the conversion of estrogens to estradiol, or block the effects of estradiol.
In some cases, women can benefit from an oophorectomy (ovaries removal surgery), especially if they have been diagnosed with an estrogen-sensitive type of cancer, such as breast cancer. This surgery causes what is known as surgical menopause.
Further Testing Related to Abnormal Estradiol Levels
Other tests should also be performed to adequately assess any conditions or diseases that can cause an estrogen-related hormone imbalance.
These tests may include: progesterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, androstenedione, sex hormone-binding globulin, and dehydroepiandrosterone (DHEA).
When estradiol is imbalanced, certain health alterations occur, including infertility, osteoporosis, and increased risk of blood clots or stroke, among others. The causes of estradiol imbalance are varied and depend on the individual’s sex and age.
Symptoms and signs of estradiol imbalance in men include gynecomastia (enlarged breast); and in women include abnormal vaginal bleeding, amenorrhea, and delayed or early menarche.
Treatment is focused on restore estradiol levels to a normal value, and several drugs can be used depending on each particular case. Under certain conditions, an ovaries removal surgery may be needed to accomplish that.
If you want to find out more about estradiol and how to maintain healthy levels of it, click here to read all about it!
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