If You Find a Breast Lump While Breastfeeding

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During your breastfeeding experience, you may notice breast lumps that can make feeding your baby challenging and even painful. Rest assured that these lumps are usually not serious, and most are temporary. While some lumps go away without treatment, others may require a trip to the doctor.

There are many types of lumps and other breast changes that can happen during breastfeeding. Plugged milk ducts, engorged breasts, and mastitis are a few of the possibilities, and all can present as a breast lump. The good news is they respond well to treatment.

Other changes in your breasts, however, may signal issues that are not related to breastfeeding. While most of the time breast lumps are nothing to worry about, in rare instances they may be serious and require medical attention.

what to do about breast lumps during breastfeeding
Verywell / Brianna Gilmartin 

Plugged Milk Duct

Plugged milk ducts are usually small, hard, and tender nodules or lumps in the breast. Often appearing suddenly, plugged ducts do not drain properly and can prevent the flow of breast milk. You may experience swelling, redness, and pain with this condition.

The following factors can cause plugged milk ducts:

  • Breast engorgement
  • Breastfeeding only on one side, preventing the other side from emptying
  • Improper breastfeeding latch
  • Infrequent or irregular feedings
  • Tight-fitting bras or sports tops

Most plugged ducts resolve without treatment after a few days because the act of emptying the breast through breastfeeding or pumping will often clear the blockage. In the meantime, holding a warm compress on the affected area can provide relief.

If it's not too painful, start your baby's feeding on the side with the plugged duct. Their strong suck at the beginning of feeding can help remove the blockage faster. Also try massaging the affected breast from your chest down to the nipple, both before and after feeding.

You may also want to use different breastfeeding positions, which can help drain different areas of the breast. And remember to wear a comfortable bra that is not too tight to prevent further problems.

Using a breast pump after you breastfeed can also help fully drain the breast and remove clogs.

Mastitis

Mastitis is an infection in the breast. Bacteria entering through a cracked nipple can allow the infection to develop; engorgement and incomplete draining of the breasts are other potential causes.

A lump associated with mastitis is painful, and the surrounding area may be warm and red. Mastitis can be accompanied by a fever, chills, fatigue, body aches, nausea, and other flu-like symptoms.

In extreme cases, it can cause painful, swollen lymph nodes in the armpit near the infected breast, an increased heart rate, or a breast abscess. Antibiotics are sometimes needed to heal a breast infection, so it's important to see your doctor if mastitis symptoms do not go away within 24 hours.

Not only is it safe to continue breastfeeding your baby if you have mastitis, it's recommended by doctors. Breastfeeding may help clear the infection by regularly removing milk from the breasts.

The milk you produce while you have a breast infection won't harm your baby. However, because mastitis can change the milk's flavor, your baby may refuse it. If that's the case, you can use a pump or hand express the milk and feed your baby previously pumped and stored breast milk, donor milk, or formula until the infection clears up.

As with plugged milk ducts, avoid tight clothing and bras that could put pressure on the affected area. This is important not only while you have the infection, but also after. Excess pressure on tender breast tissue can lead to and exacerbate mastitis.

Cyst

A cyst is a harmless round or oval lump that contains fluid. When cysts occur in the breast tissue of a lactating person, they are most often galactoceles, or milk-filled cysts that come from a blocked milk duct. One unique characteristic of galactoceles is that they often occur just after a person has discontinued breastfeeding.

These cysts can feel hard or soft and can be easily moved around inside the breast. They are typically larger than plugged milk ducts, and they may or may not be painful. As the cysts fill up with milk, they can change size. Galactoceles can be drained if they are causing pain or discomfort; using cold compresses or ice packs can also provide relief.

Galactoceles don't usually pose any problems, but they should always be examined by a doctor to ensure an accurate diagnosis. If your doctor needs to perform any tests to rule out other conditions, you should not have to stop breastfeeding.

Ultrasounds, mammograms, needle biopsies, lumpectomies, and blood tests can all be done safely while you continue to nurse.

Fibrocystic Breasts

Some women have dense breast tissue, known as fibrocystic breasts, that may become tender and feel like multiple small hard nodules in one or both breasts. Women with this condition may experience increased tenderness and lumpiness before menstruation.

Fibrocystic breasts are thought to be caused by hormone fluctuations. While you can feel the dense uneven tissue during your breast self-exam, only a mammogram can diagnose the condition.

Whereas plugged ducts are usually one or two hard, well-defined lumps, fibrocystic breast tissue is lumpy all over, especially in the outer and upper parts of the breast.

Fibrocystic breasts are quite common in younger women, and the American College of Obstetricians and Gynecologists (ACOG) notes that nearly half of women 40 and older have fibrocystic breasts.

This benign breast condition is not associated with pregnancy or breastfeeding, and it should not affect your breastfeeding experience. Because fibrocystic breast tissue can mimic or mask the signs of breast cancer, however, your doctor will want to see you regularly for screenings.

Lipoma

Lipomas are non-cancerous, fatty masses that grow slowly just under the skin. They are often soft and doughy, easily moveable, and most are painless unless they compress a nerve. Lipomas can appear in breast tissue and on other parts of your body including your neck, shoulders, arms, and thighs.

Although the cause of lipomas is unknown, this condition is hereditary (e.g. members of the same family have a higher chance of developing it). Treatment is usually not necessary for lipomas unless they cause pain or discomfort.

While harmless, lipomas can resemble a rare type of cancer called liposarcoma. See your doctor if you notice any type of lump in your breast to have it checked out.

Hematoma

A hematoma is a collection of blood that pools under the skin in an area outside of the blood vessels. Hematomas are nearly always the result of bleeding caused by trauma or breast surgery

Hematomas usually develop in 7 to 10 days after surgery, and they can be small or large. You may feel a swollen spot that is fluid-filled. The surrounding area is often painful, and it may also be red or swollen. If the blood is close to the skin, the area may look discolored or bruised. 

If you notice signs of a hematoma developing, call your doctor, as some cases may require surgical drainage.

Bruise vs. Hematoma

Bruises are caused by injured vessels and capillaries (tiny blood vessels) just under the skin. Unlike hematomas, bruises do not cause swollen lumps and are not fluid-filled. You may experience bruising during lactation if:

Slight discoloration on your breast (especially around the nipple and areola) is most likely a bruise rather than a hematoma.

Tumor

According to medical experts, the most common type of tumor in breastfeeding people is a lactating adenoma. This benign tumor feels like a solid mass under the skin with definite borders, and it is easy to move.

Lactating adenomas are commonly caused by hormonal changes in pregnancy and lactation, and they account for about 70% of the breast lumps biopsied in lactating people.

Fibroadenomas are another common type of benign breast tumor. These feel like round, hard, moveable tumors under the skin and often do not require treatment (although this depends on the type of fibroadenoma). It is not uncommon for an existing fibroadenoma to grow during pregnancy and lactation and shrink afterward, possibly due to fluctuations in hormones.

Most breast lumps turn out to be nothing serious, but about 20% of lumps are malignant (cancerous). A malignant mass may appear as a hard, painless lump that does not seem to have a definite border. It may also feel as if it is attached to the surrounding breast tissue, making it difficult to move.

When dealing with cancer, early detection is very important. If you are diagnosed with breast cancer while you are breastfeeding, you and your doctor will decide on the best course of action. You may need to stop breastfeeding if your treatment includes chemotherapy and/or radiation.

Continue to do regular breast self-exams while breastfeeding to monitor your breasts for possible lumps and other changes. This practice can help catch any potential cancerous growths early.

A Word From Verywell

Most breast lumps that occur while breastfeeding are harmless and temporary. Still, it's a good idea to keep an eye on the size and texture of any lump you find, and contact your doctor or lactation consultant with any concerns.

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8 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. WIC Breastfeeding Support. U.S. Department of Agriculture. Plugged ducts, mastitis, and thrush.

  2. University of Michigan Medicine. Mastitis while breastfeeding. Updated October 8, 2020.

  3. Teberian I, Bhimani C, Sciotto M, Wilkes A, Germaine P. Breast masses in pregnancy and lactationJ Am Osteopath Coll Radiol.  2019;8(1):5-16.

  4. Johns Hopkins Medicine. Fibrocystic breast changes.

  5. Cleveland Clinic. Fibrocystic breast changes. Updated April 9, 2014.

  6. American College of Obstetricians and Gynecologists. Dense breasts. Published October 2020.

  7. Cleveland Clinic. Lipoma. Updated October 13, 2020.

  8. Cleveland Clinic. Fibroadenomas of the breast. Updated January 9, 2021.

Additional Reading
  • American Academy of Pediatrics. New Mother’s Guide To Breastfeeding. Bantam Books. New York. 2011.