FSH, LH, Prolactin & TSH
Understanding FSH, LH, Prolactin & TSH
What is FSH, LH, Prolactin & TSH?
The Hormonal Profile Test, encompassing Follicle-Stimulating Hormone (FSH), Luteinizing Hormone (LH), Prolactin, and Thyroid-Stimulating Hormone (TSH), assesses the levels of key hormones that help regulate reproductive functions, thyroid function, and lactation. The test is vital for detecting and monitoring hormonal disorders, fertility issues, and thyroid dysfunction.
FSH, LH, prolactin, and TSH are all produced in the anterior pituitary gland and play vital roles in reproductive health, endocrine regulation, and overall well-being. Assessing their levels with this hormonal panel is often the first step in determining fertility in both men and women.
FSH is crucial for the development of eggs, regulating menstrual cycles in females and sperm production in males. LH encourages the release of an egg from the ovary in females and stimulates testosterone production in males. Abnormal levels of FSH and LH can indicate menstrual irregularity, fertility issues, and conditions such as polycystic ovary syndrome (PCOS) and pituitary disorders.
Prolactin is a hormone that stimulates breast development and milk production (lactation) in females. Additionally, it also influences the menstrual cycle. Elevated prolactin levels can interfere with fertility, cause menstrual irregularities, and be associated with conditions such as galactorrhea (inappropriate milk production) and pituitary tumors (prolactinomas).
TSH regulates the production of thyroid hormones (T3 and T4), influencing metabolism and energy levels. Abnormal TSH levels may indicate thyroid disorders, such as hypothyroidism (elevated TSH) or hyperthyroidism (decreased TSH).
In women, the doctor may suggest this test in case of symptoms of irregular or heavy menstrual periods, PCOS/PCOD, if you are facing difficulty in getting pregnant, and/or if pituitary or hypothalamus problems are suspected. In men, this test can be performed when fertility issues and signs of low testosterone levels, such as decreased sex drive and low muscle mass, are observed.
Overnight fasting is required for this hormonal profile. Do not eat or drink anything other than water for 8-12 hours before the test. In women, the preferred time to collect the sample is the second or third day of the menstrual cycle. Your doctor may ask you to temporarily stop taking certain medications, such as birth control pills, as they may lead to some aberrancy in your test results. Prolactin levels can vary throughout the day as prolactin is secreted episodically and may be influenced by factors such as stress, exercise, and sleep. Therefore, multiple prolactin tests may be needed to confirm the diagnosis.
Test result ranges are approximate and may differ slightly between labs depending on the methodology and laboratory guidelines. Talk to your doctor about your specific test results. The results will help them determine your medical condition and formulate your treatment plan.
What is FSH, LH, Prolactin & TSH used for?
An FSH, LH, Prolactin & TSH test is done to:
- Evaluate infertility issues in males and females.
- Assess menstrual irregularities and conditions such as amenorrhea or oligomenorrhea.
- Diagnose and manage conditions such as hypothyroidism or hyperthyroidism and monitor the effects of treatment in patients with thyroid diseases.
- Investigate the cause of abnormal breast milk discharge (galactorrhea) in non-pregnant women.
- Evaluate the role of prolactin in case of lactation failure in women after childbirth.
- Diagnose disorders or tumors of the pituitary gland or diseases involving the testes or ovaries.
What does FSH, LH, Prolactin & TSH measure?
Contains 4 testsThe hormonal profile measures the amount of hormones, Follicle-Stimulating Hormone (FSH), Luteinizing Hormone (LH), Prolactin, and Thyroid-Stimulating Hormone (TSH), to determine your reproductive health. This test is performed to address health issues such as delayed puberty, irregular menstruation, abnormal breast milk discharge, loss of libido, erectile dysfunction, and problems related to fertility.
These hormone levels are usually low at a young age, but the brain starts producing gonadotropin-releasing hormone (GnRH) as adolescence approaches. GnRH is responsible for initiating the changes in puberty and signaling the pituitary gland to release FSH and LH into your blood.
Follicle Stimulating Hormone
The Follicle Stimulating Hormone test measures the level of FSH in your body. FSH is produced and subsequently released into the blood by the pituitary gland. Its production is controlled by a feedback mechanism involving a hormone situated in the hypothalamus in the brain. The released FSH travels through your blood and then attaches to receptors in the ovaries and testes. It exerts functional effects on the reproductive organs, such as sexual development, puberty, and maturation. FSH levels vary throughout the menstrual cycle in response to estradiol and progesterone. Any disruption or issue in this feedback mechanism can prevent the normal function of the testicles or ovaries. Thus, determining its level provides crucial information regarding your health.
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TSH (Thyroid Stimulating Hormone) Ultrasensitive
The TSH (Thyroid Stimulating Hormone) Ultrasensitive test measures the levels of TSH hormone in the blood. TSH is produced by the pituitary gland located in the brain. Its function is to stimulate and regulate the functioning of the thyroid gland. It signals the thyroid gland to increase or decrease the production of thyroid hormones T3 and T4 (essential for regulating our body’s metabolism, temperature, heart rate, and growth) when their levels are low or high, respectively. Therefore, when the levels of T3 & T4 decrease, the pituitary gland is stimulated to release TSH. This high TSH level, in turn, stimulates the thyroid gland to release more thyroid hormones (T3 & T4); the vice-versa happens when the levels of thyroid hormones increase.
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Serum Prolactin
The Serum Prolactin test measures the levels of prolactin hormone in a person’s body. During pregnancy, prolactin, estrogen, and progesterone hormones stimulate breast milk development. Following childbirth, prolactin helps initiate and maintain the breast milk supply. If a woman does not breastfeed, her prolactin concentration will soon drop back to pre-pregnancy levels.
Besides pregnancy, the most common cause of elevated prolactin concentration is prolactinoma, a prolactin-producing tumor of the pituitary gland. Prolactinomas are the most common type of pituitary tumor and are usually benign (non-cancerous). They develop more frequently in women but are also found in men.
If the pituitary gland and/or the tumor enlarge significantly, it can put pressure on the optic nerve, causing headaches and visual disturbances, and can interfere with the other hormones that the pituitary gland produces.
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Luteinising Hormone
The Luteinising Hormone test determines the level of luteinizing hormone that promotes the functioning of the gonads, i.e., testes in men and ovaries in women. LH is produced by the pituitary gland, a pea-sized gland situated at the base of the brain. The production and release of LH are controlled by a system known as the hypothalamic-pituitary-gonadal axis. A hormone called GnRH is released from the hypothalamus of the brain and binds to the cell receptors in the anterior pituitary gland, which in turn prompts the synthesis and release of luteinizing hormone. LH then travels across the blood and attaches to its target cells in the testes in men and ovaries in women to facilitate optimal sexual and reproductive activities.
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Interpreting FSH, LH, Prolactin & TSH results
Interpretations
The reference range of FSH is age- and gender-specific. As for women, the reference range is menstrual cycle phase-specific.
The reference range for follicle-stimulating hormone (FSH) is as follows (3rd generation immunochemiluminescence assay):
Females
- Age 0-7 years: <6.7 mIU/mL
- Age 8 years to adult:
- Follicular phase: 3.1-7.9 mIU/mL
- Ovulation peak: 2.3-18.5 mIU/mL
- Luteal phase: 1.4-5.5 mIU/mL
- Postmenopausal: 30.6-106.3 mIU/mL
Males
- Age 0-7 years: <6.7 mIU/mL
- Age 8 years-adult:1.3-19.3 mIU/mL
The following values are considered to be normal, LH blood levels measured in international units per liter (IU/L):
Women:
- The follicular phase of the menstrual cycle: 1.9 to 12.5 IU/L
- LH surge: 8.7 to 76.3 IU/L
- The luteal phase of the menstrual cycle: 0.5 to 16.9 IU/L
- Pregnancy: less than 1.5 IU/L
- Post-menopause: 15.9 to 54.0 IU/L
- Women using contraceptives: 0.7 to 5.6 IU/L
Men:
- The age group of 20 and 70 years: 0.7 to 7.9 IU/L
- >70 years of age: 3.1 to 34.0 IU/L
The following values are considered to be normal, prolactin blood levels measured in international units per liter (ng/mL):
Patients (Age) Reference Range(s)
Males ≤ 18 Years |
|
Tanner Stage 1 (< 9.8 Years) Tanner Stage 2 (9.8 - 14.5 Years) Tanner Stage 3 (10.7 - 15.4 Years) Tanner Stage 4 (11.8 - 16.2 Years) Tanner Stage 5 (12.8 - 17.3 Years) Males > 18 Years
|
< 10 ng/mL < 6.1 ng/mL < 6.1 ng/mL 2.8 - 11.0 ng/mL 2.8 - 11.0 ng/mL
2.10 - 17.70 ng/mL |
In Females ≤ 18 Years |
|
Tanner Stage I (< 9.2 Years) |
3.6 - 12.0 ng/mL |
Tanner Stage 2 (9.2 - 13.7 Years) |
2.6 - 18.0 ng/mL |
Tanner Stage 3 (10 - 14.4 Years) |
2.6 - 18.0 ng/mL |
Tanner Stage 4 (10.7 - 15.6 Years) |
3.2 - 20.0 ng/mL |
Tanner Stage 5 (11.8 - 18.6 Years) |
3.2 - 20.0 ng/mL |
Adult Females Non Pregnant |
2.80 - 29.20 ng/mL |
Pregnant Post Menopausal |
9.70 - 208.50 ng/mL 1.80 - 20.30 ng/mL |
The following values are considered to be normal, TSH blood levels measured in international units per liter (mIU/L):
Patients (Age) Reference Range(s)
Premature Infants (28-36 Weeks) |
|
1st Week of Life |
0.20-27.90 mIU/L |
Term Infants (>37 Weeks) |
|
Serum or Cord Blood |
1.00-39.00 mIU/L |
1-2 Days |
3.20-34.60 mIU/L |
3-4 Days |
0.70-15.40 mIU/L |
5 Days-4 Weeks |
1.70-9.10 mIU/L |
1-11 Months |
0.80-8.20 mIU/L |
1-19 Years |
0.50-4.30 mIU/L |
≥20 Years |
0.40-4.50 mIU/L |
Pregnancy |
|
First Trimester |
0.26-2.66 mIU/L |
Second Trimester |
0.55-2.73 mIU/L |
Third Trimester |
0.43-2.91 mIU/L |
A lower TSH level than the normal reference range indicates hyperthyroidism.
A higher TSH level than the normal reference range indicates hypothyroidism.
Note: TSH levels show circadian variation (fluctuates during the 24-hour cycle), reaching peak levels between 2-4 am and at a low between 6-10 pm.
The reference range may vary from lab to lab*