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Your New Breastfeeding Vocabulary

What do colostrum, letdown, and transitional milk have in common? They’re all part of your new breastfeeding vocabulary.

When you learn how to breastfeed, you do more than learn how to latch. You learn how to speak a whole new language.

That’s right. Breastfeeding has a vocabulary all its own. We’re here to help you get up to speed on all the words you need to know to become fluent.

A is for:


Breastfeeding isn’t really about the nipple—it’s about the area around your nipple, more scientifically known as your areola. Your areola is the darker skin circling your nipple, and it’s essential for getting a good latch. Your baby should take both your nipple and at least some of your areola into their mouth to transfer milk effectively.

Another important fact about your areola? You have something called milk sinuses underneath your areola. Learn more below.


Where does breast milk come from? Alveoli! Alveoli are tiny sacs in the mammary gland that produce and store milk. They’re able to do this thanks to prolactin—which helps your alveoli pull nutrients from your blood supply and turn them into milk—and oxytocin—which causes cells surrounding your alveoli to contract and move milk down the milk ducts via the letdown reflex.

B is for…

Breast pump

Some parents may not be able to nurse. Others may need to be away from their baby. Still others may need to boost their milk supply.

Whatever the reason, breast pumps allow parents to provide breast milk for their babies.

If you’re in the market for a breast pump, you have options:

  • Manual vs. electric
  • Single vs. double
  • Cord-free vs. plugin
  • Commercial vs. hospital grade

Don’t forget—the Affordable Care Act (ACA) has mandated that health insurance providers cover the cost of a breast pump.

Breast crawl

When placed on the birthing parent’s abdomen or chest following birth, babies have the innate ability to crawl up to the breast and latch, thereby initiating their first breastfeeding session.

The breast crawl can be a powerful and empowering experience for new parents, but don’t be discouraged if it doesn’t happen for you—there are many variables in each birth story!

C is for…


Colostrum is the first milk of your breastfeeding journey. Your body starts producing colostrum around 16 weeks of pregnancy, and it’s the milk your baby will get when they latch on for the first time.

Colostrum is thick and sticky, particularly compared to higher-in-water-content transitional and mature milk. It’s full of protein, fat-soluble vitamins and minerals, and critical immunoglobulins that protect your baby and support their immune system.

When it comes to colostrum, many new breastfeeding parents are worried about quantity. Don’t! While your body doesn’t make a whole lot of colostrum, it’s plenty for your baby’s tiny stomach.

Clogged milk ducts

Clogged ducts are precisely what they sound like—clogged milk ducts that prevent your breast milk from flowing freely. They occur for various reasons: missing a nursing or pumping session, a poor latch by your baby, or wearing constricting bras.

If you’re experiencing clogged ducts, don’t be shy about reaching out to lactation consultants for help. While painful, they can be treated effectively with techniques like breast massage, moist heat, and lots and lots of nursing or pumping. Lactation consultants can help you figure out the best way to treat yours. (And make sure to treat them—left untreated, clogged ducts can lead to mastitis.)

Cluster feeding

If your baby is nursing more than usual, you may be experiencing a period of cluster feeding. The term cluster feeding refers to a period where your baby has a higher-than-usual demand for nursing. Cluster feeding can occur before a growth spurt but can also happen during times of stress or transition for your baby.

E is for…

Exclusive breastfeeding

If your baby receives only breast milk, you’re exclusively breastfeeding (also referred to as EBF). That means no solids, formula, or anything else. That being said, you can provide breast milk, however, it works best for you. Nursing, pumping and bottle feeding, combo feeding—it’s all breastfeeding.

The World Health Organization (WHO) and the Center for Disease Control (CDC) recommend that babies are exclusively breastfed for the first 6 months of their lives, followed by breastfeeding alongside adequate food for at least twelve months (CDC) or two years (WHO).


Feeling overfull of milk? You might be experiencing engorgement. Engorgement happens when milk production exceeds milk removal. As a result, your breasts end up sore, swollen, hard, red, and uncomfortable. Thankfully, the solution is simple: remove the milk. You can nurse, pump, or hand express to get relief.

Engorgement frequently happens at the beginning of your breastfeeding journey when your colostrum shifts to transitional milk, but it can occur anytime if you miss a nursing or pumping session. The effects can go beyond engorgement—it can lead to clogged ducts, mastitis, reduced milk supply, and more.

Exclusive pumping

Many parents also use pumping as the foundation of their breastfeeding journey. Whether for medical reasons, returning to work, or other personal reasons, exclusively pumping is an excellent way to continue giving your baby the many benefits of breast milk.

Extended breastfeeding

If you’ve breastfed your child for more than a year, you’ve officially practiced extended breastfeeding. Extended breastfeeding looks different for each family. For some parent/baby dyads, it can mean nursing until their baby reaches 15 months. For others, it can mean nursing for 3 years and beyond. Extended breastfeeding can have its challenges, but breastfeeding offers nutritional, emotional, and immune system benefits at all ages.

F is for…


Is pumping part of your breastfeeding journey? If so, flange is an excellent word to have in your vocabulary. The flange, also known as a breast shield, is an integral part of your pumping kit. It fits over your nipple and areola to form a seal, helping to pull milk through your milk ducts and out your nipple.


When you begin a nursing or pumping session, the milk that comes out is generally lower in fat content and higher in milk, sugar, and lactose than the milk that comes out at the end. This milk is often referred to as foremilk. (The milk at the end of the session, on the other hand, is hindmilk.)

Depending on how long you go between nursing or pumping sessions, your foremilk may have higher or lower fat content. That’s because milk expressed from empty breasts tends to be fattier than that from full breasts.

Another point to remember is that the shift from foremilk to hindmilk isn’t abrupt. It’s not like turning on a light switch. Instead, it’s more like a dimmer switch that gradually transitions from light to dark.

G is for…


Building a plentiful milk supply is a top priority for breastfeeding parents. The best way to do this? Empty your breasts as fully as possible and as much as possible.>

But breastfeeding parents sometimes need a little extra support, and for some parents, turning to galactagogues—foods, supplements, or medicines to increase their milk supply—may help. Popular options include oats, leafy greens, fennel, garlic, ginger; herbal supplements like fenugreek, blessed thistle, or alfalfa; and prescription medication domperidone or Reglan.

Galactagogues can be controversial—their benefits mostly haven’t been proven through clinical research. If you’re worried about your milk supply and want to explore your options, make an online appointment with one of our IBCLCs.

H is for…


Compared to foremilk, hindmilk is the milk that comes at the end of a feed. Hindmilk is thicker and richer in fat, but it’s still the same breast milk as foremilk.

Hand expressing

Hand expressing milk is a helpful breastfeeding technique for all parents to master. While babies are the best (and cutest) removers of milk and breast pumps are handy tools, hand expressing can help eliminate clogs during the weaning process, and more.

I is for…


We’ll be honest: There’s still a lot to learn about breast milk. Researchers regularly discover new and fascinating information about the benefits of breastfeeding. But one area that constantly amazes us is how breast milk supports your baby’s immune system.

Via colostrum, the first milk your breasts produce, you provide antibodies that prime your newborn’s immune system. These antibodies come from the makeup of breast milk and your immune system; you can pass on some protection from previous illnesses to your baby during breastfeeding.

Inverted nipple

Breasts come in all shapes and sizes. So do nipples! One way nipples present is in a retracted or inverted form. Inverted nipples are entirely normal but can make latching more difficult for your baby. If you have inverted nipples, working with an IBCLC can help you figure out the best way to achieve your breastfeeding goals.


What is an IBCLC? Or more precisely, who is an IBCLC? This acronym stands for International Board Certified Lactation Consultant. An IBCLC completes 95 hours of training and up to 1000 hours of clinical practice, health-related coursework and passes an exam before receiving certification.

The IBCLC certification is internationally recognized. As such, practitioners have to follow the evidence-based professional standards of their field when helping parents and babies in their breastfeeding journeys. This isn’t a one-and-done designation either. IBCLCs have to renew their certification every 5 years.

K is for…

Kangaroo care

Babies born prematurely or who have to be placed in the NICU due to medical reasons need extra care to thrive. Parents often feel helpless in these situations, but there’s one beneficial practice that parents can engage in to support their little one: Kangaroo care.

Kangaroo care is essentially skin-to-skin care for NICU babies. It can help parents bond with their baby, but it also helps regulate the baby’s temperature and heart rate and supports breastfeeding and milk production.

L is for…


Lactation. It’s what we at Nest Collaborative are all about. Lactation, clinically speaking, is the production and removal of milk from breasts. But it’s so much more than that!

Lactation is fascinating for lots of reasons. Here are just a few that come to mind:

    • You begin producing milk around 16 weeks of pregnancy, although it’s colostrum rather than mature milk.
    • You can produce milk without giving birth, and you can make milk even if your milk supply has dried up in a process known as relactation.
    • Your breast milk will change in composition over time to meet your baby’s needs.

Learn more about what makes milk production so unique.

Lactation consultant

A lactation consultant is a trained professional who provides breastfeeding support. But hold up. This isn’t the same thing as an IBCLC. It’s the whole, not-all-thumbs-are-fingers-but-all-fingers-are-thumbs situation. All IBCLCs are lactation consultants, but not all lactation consultants are IBCLCs.

There’s a range of different professional designations in the lactation consultant industry. Some lactation professionals are Certified Lactation Counselors (CLCs), meaning they’ve passed 52 hours of training and a certification exam. They’re highly qualified and knowledgeable in their field and an excellent resource for breastfeeding parents. There are also Certified Breastfeeding Specialists (CBSs), Certified Lactation Educators (CLEs), and Certified Lactation Specialists (CLSs).


Latching is a critical part of breastfeeding. A deep latch helps your baby stimulate milk production, transfer milk, and establish a strong milk supply by fully emptying your breasts. It also helps prevent nipple pain, clogged ducts, mastitis, and other breastfeeding problems.

If you’re experiencing pain while breastfeeding, one of the first things you should investigate is your baby’s latch. A proper latch should be pain-free and comfortable. While anatomical issues like a tongue-tie can affect latch, an IBCLC can help teach you and your baby how to latch well.

Letdown reflex

When your body releases milk from your breast during nursing or pumping, it’s thanks to your letdown reflex. Some breastfeeding parents report feeling a tingly, pins-and-needles sensation during their letdown. Other parents don’t notice it at all. (This is especially the case for those who have breastfed previously or have nursed their baby for more extended periods.)

In some cases, the breastfeeding parent may have what’s known as an overactive letdown. This means that breast milk is released too quickly for a baby to drink comfortably, causing them to choke, sputter, or gag. However, you can reduce an overactive letdown by pumping or hand expressing a bit of breast milk before feeding.


Lip-tie conditions are a common breastfeeding issue. Lip-ties occur when the frenulum—the tissue behind a baby’s upper lip—is too thick or stiff. While li- ties are less problematic than tongue-ties, they often present in tandem with tongue-ties. As with tongue-ties, lip-ties can be fixed through revision surgery, but it’s essential to consult with an IBCLC and/or a pediatric dentist to understand the extent of the problem before making any decisions.

M is for…


Getting mastitis can feel like a breastfeeding trial by fire. Literally. Mastitis is a painful inflammation of the breast that frequently occurs in breastfeeding parents. Often the result of clogged ducts, insufficient milk removal, or bacteria entering the breast is treatable and requires prompt attention.

If you notice systems such as redness, soreness, hard or tender lumps in your breast, painful nursing, an elevated temperature, or feeling rundown, you may have mastitis. To resolve, nurse frequently, rest and massage hard spots on your breast to make sure you’re keeping your milk flow going. If you’re still feeling poorly after a few days, contact an IBCLC or your healthcare provider—some cases of mastitis can require antibiotics to resolve.

Milk blister

Also known as a bleb or nipple blister, milk blisters are when a thin layer of skin forms over the top of a milk duct on your nipple. Milk blisters may or may not be painful, but they can seem to pop up out of nowhere. However, they often resolve on their own. If they don’t, applying moist heat can help open up the duct.

O is for…


When your baby nurses, your brain releases two important breastfeeding hormones: prolactin and oxytocin. Also known as the “love” hormone, oxytocin is released following birth and during breastfeeding. Oxytocin is important for creating a bond with your baby, decreasing pain and stress in both parent and baby, and helping you recover from childbirth.

Oxytocin is also responsible for helping your muscles relax during breastfeeding, allowing your letdown to happen.

P is for…


Your other nursing hormone, prolactin, is the hormone responsible for telling your alveoli to make milk. Your prolactin levels are higher in the early (very early) morning, meaning that your milk volume tends to be higher.

T is for…


Tongue-ties are common, or at least frequently diagnosed, breastfeeding challenge. Tongue- ties occur when the tissue that connects your baby’s tongue to the floor of their mouth is short or tight. As a result, they may struggle to latch correctly, creating pain and discomfort for the breastfeeding parent, reducing milk supply, and creating a whole range of risks.

Tongue-ties can be resolved with a tongue-tie revision surgery, but note that not all tongue-ties require a revision! Read more about tongue-ties. If you’re worried your baby may have a tongue-tie, make an appointment with an IBCLC or a pediatric dentist.

Tandem feeding

Do you have multiples? Or have an older nursling? You may choose to tandem feed as a way to provide breast milk to two or more children. Tandem feeding can be incredibly rewarding, but some parents can feel overwhelmed by it. If you are, know that help is just an IBCLC appointment away.

Transitional milk

Transitional milk is the second type of breast milk you produce following colostrum. Transitional milk is waterier than colostrum but is high in fat, vitamins, and calories to support your growing newborn.

W is for…


Weaning is a term that gets misused frequently. Clinically, weaning takes place when you start replacing breastfeeding with other sources of nutrition. This means when you give your baby their first slice of banana, avocado, spinach/beet/berry puree, you’ve started weaning them.

But just as frequently, we use weaning to refer to when the parent-baby breastfeeding dyad ends their breastfeeding relationship. Some children self-wean quickly. Others are breastfeeding enthusiasts into their 3s and 4s or beyond. As the World Health Organization states, “Breastfeeding should be continued, with appropriate complementary foods, for as long as the breastfeeding parent and infant mutually desire.” We completely agree—as long as BOTH parent and baby want and can breastfeed, there shouldn’t be a rush to wean.

When the time comes to wean, it can be helpful to discuss the process with an IBCLC. Working with an IBCLC can help you develop a plan to wean that avoids engorgement, clogged ducts, and mastitis.

Have questions? Need help? Want to expand your breastfeeding vocabulary even further? Make a convenient online video appointment with one of our IBCLCs today.

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