Prolactin Levels

What is Prolactin?

Prolactin is a lactogenic hormone, which is secreted from the pituitary gland, present in the hypothalamus of the brain. Usually in both the gender, men and women have a small quantity of prolactin in their blood stream. In women, prolactin hormone helps to maintain the menstrual cycle.

In men, sperm production is affected by prolactin hormone. The main physiological function of this hormone is activated of the mammary gland of the women and increase production and secretion of milk after childbirth.

Prolactin test is conducted to estimate the prolactin level in the physiological system. However, prolactin level can help to measure the sexual satisfaction for both the gender. ^(1,2)

The process of prolactin test conduction

The prolactin test is conducted in the clinical laboratory. The health professionals follow the subsequent steps to conducting prolactin test:

• Prolactin test is a blood test, so the withdrawal of blood is the first step. For this elastic thin band is warped at the upper arm to block the blood circulation and make the vein prominent, which helps to ease withdrawn of blood.
• Then the injection site is sterilized with alcohol swab.
• Take a disposable needle and syringe set and carefully put the needle in the vein. May sometimes more than one try need to conduct for smoother blood withdrawn and in that case, more than one needle require.
• Attach the blood collection tube with needle and collect sufficient blood sample for conduction of the test.
• After collection of the sample, the technician removes the band and put a cotton ball at the needle site and smoothly removes the needle also.
• Put pressure on the site of injection for stoppage of bleeding and then placed a Band-Aid. ⁽³⁾

Why Prolactin Test is recommended?

The Prolactin test  is recommended for detection of  the prolactinoma, the non-malignant tumor development in the pituitary gland. The prolactin test is also routinely conducted for the patient, who has the positive result of prolactinoma to understand the treatment response.

Symptoms in Women

The symptoms associated with prolactinoma in women are

• Headache
• Visual disturbance
• Lactation without pregnancy

Symptoms in Male

The symptoms associated with male are

• headaches
• Visual disturbance
• Libido (reduced sex drive) or infertility problems due to erectile problem

Other than this, the following conditions also need to check the prolactin level

• Galactorrhea or breast milk production without childbirth.
• Libido (decreased sex compel) for both the genders
• Losing of erection during intercourse in men.
• Infertility (Female unable to bear the child at the childbearing age) Not able to get pregnant)
• Amenorrhea (absence or irregular menstrual cycle) ^(1,4)

Normal ranges in Men, Women

The normal value of the prolactin level is expressed in a range. It is not constant for every clinical laboratory test result. Different laboratory uses different techniques or machine, so the test result varies. Therefore, every laboratory test result mentioned their normal range in the clinical test result report. The usual considerable normal range of prolactin test result is given below and it varies with age, gender and clinical conditions.^(1,4)

Men	2-18 mcg/L or 2-18 ng/mL
Non-pregnant women	2 – 29 mcg/L or 2 – 29 ng/mL
Pregnant women	10 – 209 mcg/L or 10 – 209 ng/mL
Children	3.2-20 mcg/L or 3.2-20 ng/mL

High Prolactin level

Usually the prolactin level in the blood is less in men and non-pregnant women, even the prolactin level varies within the 24 hours of a day and it depends when the blood sample is collected. The prolactin level is raising up during sleeping and it becomes higher in  the morning. Usually,  3 to 4 hours after waking the blood sample  is collected.

The normally prolactin level is high during pregnancy and lactation period after childbirth.

Causes

The following are the medical conditions, in which high level of prolactin is associated:

• prolactinomas (benign tumor in the pituitary gland)
• Ailment in the hypothalamus
• The anorexia nervosa (eating disorder)
• Malfunction in thyroid gland and decrease level of thyroid hormone production (hypothyroidism)
• Renal problem
• Hepatic disorder
• POS (Polycystic ovary syndrome)
• Pituitary gland ailments
• Lung cancer
• seizures Less common
• Traumatic injury in chest wall. Read Vocal Cord paralysis

Other than above mentioned causes, the following factors also contribute in high level of prolactin hormone:

• Arousal sensation in the nipple
• Stress
• Certain drugs like estrogen containing drugs, anti- hypertensive drugs like verapamil, reserpine, methyldopa, Anti ulcer drugs like cimetidine, tricyclic antidepressants, amphetamines, risperidone and opiates. ⁽⁵⁾

Low Level of Prolactin

In case of any malfunctioning occurs in the pituitary gland, and hypo-pituitarism develops, then low level of prolactin is common.

Causes

Certain drugs can cause low level of prolactin, which include levodopa, dopamine, and ergot alkaloid derivatives. ⁽⁵⁾

References

1. Joanna Goldberg (2012); Prolactin Level Test; Retrieve from: http://www.healthline.com/health/prolactin#Overview1
2. Hyperprolactinemia (High Prolactin Levels) (2014); Retrieve from: https://www.asrm.org/FACTSHEET_Hyperprolactinemia_Prolactin_Excess/
3. WebMD Medical Reference from Healthwise (2014); Prolactin; Retrieve from: http://www.webmd.com/a to-z-guides/prolactin-15129?page=2
4. Brent Wisse (2014); Prolactin blood test; Retrieve from: https://www.nlm.nih.gov/medlineplus/ency/article/003718.htm
5. Prolactin (2014); Retrieve from: https://labtestsonline.org/understanding/analytes/prolactin/tab/test/