Looking down at your shirt and seeing two stains over the nipples can be disconcerting, to say the least. Yes, if you are breastfeeding it’s par for the course (words from girls in the know…never leave home without nipple pads postpartum!), but if you are eons away from pregnancy it can be beyond confusing. However, there are certain instances, which are not super uncommon, where this can happen. In most cases, it comes from the overproduction of a hormone produced in the brain called prolactin. Here’s a preview of what this prolactin can do.

Think Ps…prolactin is made in a part of the brain called the pituitary. While you can’t see it and probably have never even heard of it, the pituitary is a pretty powerful hormone in the world of OB/GYN reproductive hormones. The pituitary is not only known for its good looks and funny personality but also for the production of hormones that initiate periods, help with pregnancy, and promote overall health and wellness. While post-pregnancy you want that pituitary to be making prolactin in overdrive, pre-pregnancy, you don’t want to hear more than a peep from it.

Normally, prolactin production is kept in check by other hormones. They control the production and release of prolactin into the bloodstream. However, when these hormones are not functioning properly or there is a tumor that is producing prolactin, that’s when things can get milky.

Although classically we talk about women and breast discharge, in reality most women who have elevated prolactin levels may never know it. Contrary to popular belief, the levels actually need to be fairly elevated for milky breast discharge to occur (FYI: the medical term for this discharge is galactorrhea). Most women come to the doctor complaining of irregular or lack of periods and/or infertility. In the evaluation for these conditions, the elevated prolactin is identified. In many ways, it’s a good problem to have. It is most often easily fixed and causes no significant medical problems.

Prolactin tumors, prolactinomas, are some of the most common benign brain tumors. They can be small (micro) or large (macro) and are often the culprits for elevated prolactin and milky discharge from the nipples. While the word tumor can send everyone into a tizzy, they are most often treated with oral medications. The medications, bromocriptine and cabergoline, work to decrease the prolactin levels and therefore decrease the symptoms. For most women, taking them can be a no brainer—they can reduce your prolactin levels, reset the system, and ultimately turn your periods and your fertility back on.

While prolactinomas are definitely at the top of the list for causing elevated prolactin, there are other problems that could cause this problem. Culprit No. 1 is pregnancy. Even if you don’t think you could be pregnant, we are always going to ask. Other potential causes include medications (particularly antidepressants), chest wall stimulation (massage) or a lesion (think herpes zoster), hypothyroidism, or other tumors in the brain.

When trying to determine what, where, how, and why (it sounds like a game of Clue!) the prolactin is elevated, we usually start with a repeat blood test. Yes, you read that correctly. We have you come in and repeat the levels to confirm that they are actually elevated! However, this time we ask you not to eat and to come in first thing in the morning. Food and late-night fun can throw off the accuracy of the prolactin hormone test.

If the repeat levels are high, then it’s the real deal. Our next move is to send you for an MRI of the brain. This will tell us if it is coming from a benign tumor in the brain, and if so, how big it is. The bigger, the more bothersome and the better chance that you will need surgery. Luckily, most prolactinomas are “micro” (less than 1 cm), requiring only medical treatment. If the MRI is negative, we start the hunt for Professor Plum in the kitchen with the candlestick (a.k.a. we look for other potential problems).

Why do we care? Well, it’s not just that milky discharge is driving up your dry cleaning bill! It may also be preventing you from getting regular periods and getting pregnant. Additionally, no period means low estrogen, which means a risk for bone breakage. For women who are nowhere near being ready for a baby, the easiest thing to do is to put them on the birth control pill. This will control their periods and make sure they are getting the appropriate amount of estrogen. For women who are ready for a plus one, we initiate medical treatment (cabergoline or bromocriptine) to drive down the prolactin levels and allow ovulation to occur.

For many, prolactin is a word as foreign as incinta (that means pregnant in Italian!). You may never say it, hear it, or think of it. However, it doesn’t mean you won’t find yourself in Italy pregnant and need to know how to say pregnancy! In the same vein, you or one of your girlfriends may experience milky breast discharge and start to freak out.

Don’t freak out. You are not a cow. You are not alone. This is not uncommon. Go speak to your GYN—they will get to the bottom of this, get treatment going, and stop the milk from flowing.