Prolactin Test

Both men and women produce prolactin in small amounts, which can be detected in blood. Prolactin levels rise during pregnancy, and higher levels of prolactin stimulate the body for milk production during breastfeeding. Prolactinoma is a benign prolactin-producing tumour in the pituitary gland. This tumour may lead to headaches, vision problems, etc. Healthcare specialists may advise prolactin tests for diagnosing or monitoring prolactinoma. A prolactin test may also be used to evaluate irregular menstrual cycles, fertility issues, conditions affecting the thyroid, adrenal gland functioning, polycystic ovarian syndrome or anorexia. Several medications and drugs can also stimulate the pituitary gland to release prolactin into the bloodstream. A prolactin test is advised to evaluate the cause of:

• Galactorrhoea (increased breast production not associated with childbirth
• Lack of sex drive (libido) in men and women
• Problems associated with erection
• Inability to conceive
• Irregular menses
• Menopausal symptoms such as hot flashes and vaginal dryness

No special preparations are needed for this test. As prolactin levels are highest during sleep and in the morning, the doctor may ask for blood samples to be collected at a specific time. Patients must notify the physician regarding any medications and drugs that they may be taking prior to testing. Wearing short-sleeved clothes is encouraged to ease blood collection.

(Consult physician online)

Blood sample is collected from a vein of arm. Natural prolactin levels vary throughout the day. Individuals may experience mild pain due to needle insertion when drawing blood. There may be a slight bruise, which heals rapidly. Prolactin levels gradually increase through the night and are highest in the morning. Doctors usually advise the sample to be collected 3-4 hours after the person has woken up.

Normal results: Normal values of prolactin are as follows:

In Men: Less than 20 ng/mL                                              
In nonpregnant women: Less than 25 ng/mL
In pregnant women: 80-400 ng/mL

Abnormal results: Prolactin levels may be high in individuals in the following scenarios:

• Prolactinomas
• Hypothyroidism
• Diseases of the hypothalamus
• Anorexia nervosa
• Chest wall injury or irritation
• Liver diseases
• Polycystic ovarian syndrome
• Kidney disease
• Treatment with certain medications, such as antidepressants, oestrogen, H2 blockers and opiates

Higher than normal prolactin levels do not always indicate a health condition. In some cases, prolactin levels may be raised after eating or due to stress at the time of the test. Higher levels of prolactin in women can reduce oestrogen production in ovaries. Low oestrogen levels can lead to irregular periods or may stop periods completely and reduce sexual drive, leading to vaginal dryness. However, if prolactin values are about 1000 times more than normal, it could be a sign of prolactinoma, and additional tests will be needed to confirm the diagnosis. Low levels of prolactin could be due to dopamine, levodopa or ergot derivatives and usually do not require treatment.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. This information is purely from an educational perspective and is in no way a substitute for medical advice from a qualified doctor.