PROLACTIN, SERUM

A prolactin (PRL) test measures the level of prolactin in the blood. Prolactin is a hormone made by the pituitary gland, a small gland at the base of the brain. Prolactin causes the breasts to grow and make milk during pregnancy and after birth. Prolactin levels are normally high for pregnant women and new mothers

When should the prolactin test be done?

A blood prolactin test is usually done about 3 hours after you wake up, sometime between 8 a.m. and 10 a.m. Emotional stress or strenuous exercise just before the test can raise prolactin levels. You may be asked to rest quietly for up to 30 minutes before having your blood drawn

Causes of Abnormal Prolactin Levels

Normally, men and nonpregnant women have just small traces of prolactin in their blood. When you have high levels, this could be caused by:

• Prolactinoma (A benign tumor in your pituitary gland that produces too much prolactin)
• Diseases affecting the hypothalamus (The part of the brain that controls the pituitary gland)
• Anorexia (An eating disorder)
• Drugs (That are used to treat depression, psychosis, and high blood pressure)
• Chest injury or irritation (For example, scars, shingles, or even a bra that’s too tight)

Also, kidney disease, liver failure, and polycystic ovarian syndrome (a hormone imbalance that affects ovaries) all can affect the body’s ability to remove prolactin.