How Do You Know If You Have Mastitis?

Medically Reviewed on 6/10/2022

What is mastitis?

Mastitis is an inflammation of breast tissue common in new mothers that are breastfeeding. In addition to significant discomfort or pain, common signs include breast tenderness, lumps in breast tissue, and flu-like symptoms.
Mastitis is an inflammation of breast tissue common in new mothers that are breastfeeding.

A common condition among new mothers, mastitis affects approximately 1 in 10 breastfeeding women. It involves the inflammation of breast tissue and is often accompanied by moderate to severe infections.

In addition to causing significant discomfort or pain, mastitis can increase the likelihood of your prematurely quitting breastfeeding. What’s more, the condition can make you feel run down to the point where you find it difficult to properly care for or bond with your baby.

Considering the physical and emotional issues associated with mastitis, it’s important to recognize the signs early on. With prompt treatment, discomfort can be reduced so that breastfeeding becomes more enjoyable for both you and your children.

Signs and symptoms of mastitis

The most common signs of mastitis often appear without warning. These can vary from one mother to the next, but may include the following:


If you have mild or moderate mastitis, you might find that your breasts feel unusually tender, even when compared to what you might have experienced when you first started breastfeeding. For some, this sensitivity is accompanied by the breast being warm to the touch. Swelling of the breast is also common.

Lumps in the breast tissue

You may experience a general thickening of the breast tissue, or you might notice some defined lumps. These lumps may feel sore or painful. Mastitis-related lumps also oftentimes have a wedge-like appearance to them.

Pain while breastfeeding

Breastfeeding may feel extremely uncomfortable if you have mastitis. Many women complain of pain while breastfeeding. Mastitis can be difficult to detect because women with this condition may already be experiencing pain due to latching issues.

Flu-like symptoms

It’s possible you might mistake signs of mastitis for flu symptoms. If clogged ducts aren’t quickly addressed, the problem could evolve into issues such as achiness, chills, or fatigue.


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Causes of mastitis

In most cases, mastitis occurs when an infection forms because milk is trapped within the breast. However, the reasons for this problem can differ between women. Common causes include:

Blocked ducts

Prior to suffering mastitis, women often experience blocked ducts. This prevents milk from flowing properly. Blocked ducts may occur as babies’ breastfeeding habits or schedules change. This problem often happens as babies begin to sleep through the night, as you might not empty your breasts as often as you did previously. 

Signs of blocked ducts include localized pain or tenderness. If left untreated, this concern can progress to full-on mastitis. This development may occur due to bacteria entering the breast through ducts or cracks in the nipple. Diagnosis and treatments for blocked ducts are mostly the same as those recommended for mastitis, but mostly focus on localized concerns within the breast as opposed to general signs of infection. 

Milk blisters

Also known as blebs, milk blisters involve plugged nipples. They often occur in response to blocked ducts and can further increase the likelihood of eventually developing mastitis. These blisters block milk from flowing and can cause the milk to thicken. Skin sometimes grows over these blisters, thereby backing up the milk even more. 


A specific type of mastitis known as periductal mastitis may occur due to smoking. This version of the condition is believed to develop due to chemicals within cigarettes which cause inflammation and may damage milk ducts.

When to see the doctor for mastitis

Prompt medical attention is crucial as it can address not only current symptoms, but also underlying factors that may cause future problems with breastfeeding. Rather than waiting until a problem develops, it’s important to visit a doctor as soon as the signs of a clogged duct appear. For many women, it’s worth checking in with a lactation consultant if latching issues or other breastfeeding concerns prompt unusual sensations such as fullness or tenderness. 

Diagnosing mastitis

A mastitis diagnosis typically involves a combination of a physical exam and questions about signs and symptoms. Conversely, detection can also be prompt, as the infected breast may appear inflamed or swollen.

Inflammatory breast cancer is sometimes confused with mastitis so some physicians may take extra precautions by recommending mammograms or ultrasounds. Should antibiotics and other common mastitis treatments fail to resolve symptoms, a biopsy may prove necessary.

Treatments for mastitis

Mastitis treatments fulfill two main purposes: resolving the blocked ducts or milk blisters responsible for the condition and addressing the resulting infection. Infections can be resolved with a simple course of antibiotics. 

Over-the-counter pain medications can ease tenderness or swelling of the breasts. Mothers with mastitis should take care to use breastfeeding-safe medications such as acetaminophen.

Treatments should also aim to prevent future blocked ducts. Physicians may recommend strategies for relieving breast fullness including:

  • Switching nursing positions to drain the breast more evenly.
  • Pumping to drain excess milk.
  • Applying heat to clogged breasts to encourage the proper flow of milk.
  • Wearing loose clothing. 

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Medically Reviewed on 6/10/2022
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