Breast Mastitis: Causes, Symptoms & Treatment Canada

Breast mastitis is one of the most common inflammatory conditions affecting the breast, causing significant pain, swelling, and discomfort for thousands of Canadians each year. Whether you are a new mother or experiencing symptoms unrelated to breastfeeding, understanding this condition can help you seek timely care and avoid serious complications.

What Is Breast Mastitis and What Causes It?

This comprehensive guide covers everything you need to know about mastitis symptoms breastfeeding mothers frequently encounter, including the different types of breast inflammation, breast abscesses, and when to visit your family doctor or a walk-in clinic in Canada. Recognizing the early warning signs is the first step toward effective treatment and a faster recovery.

Understanding the Breast: A Quick Overview

Treatment Options for Breast Mastitis: A Comparison Guide

Treatment Option	Benefits	Considerations	Typical Duration
Antibiotics (e.g., Cloxacillin, Cephalexin)	Clears bacterial infection effectively; first-line treatment recommended by Health Canada	May affect breast milk; complete full course even if symptoms improve; inform prescriber of penicillin allergy	10–14 days
Continued Breastfeeding or Pumping	Helps drain affected breast, reducing milk stasis and easing pain; safe for infant	May be uncomfortable initially; improper latch can worsen symptoms; lactation consultant support recommended	Throughout recovery
Pain Relief (Ibuprofen or Acetaminophen)	Reduces fever, swelling, and discomfort; ibuprofen also acts as anti-inflammatory	Follow dosing guidelines; ibuprofen generally preferred for inflammation; consult pharmacist if breastfeeding	As needed, typically 3–7 days
Warm Compresses and Breast Massage	Promotes milk flow, eases blocked ducts, and provides natural pain relief	Should complement—not replace—antibiotic therapy; avoid aggressive massage on severely inflamed tissue	Multiple times daily during recovery
Surgical Drainage (for Abscess)	Necessary when a breast abscess develops; removes accumulated pus and prevents spreading infection	Required in approximately 3–11% of breast mastitis cases; performed under local or general anaesthesia at a hospital	Single procedure; follow-up care 1–2 weeks

The breast is a glandular organ found in both men and women. In women, it plays an active role in milk production. In men, it exists only in a basic, undeveloped form.

The breast sits on the front wall of the chest and contains glandular tissue, fat, and skin. The glandular tissue is organized into 15 to 20 lobes. Each lobe has its own milk duct that opens at the nipple.

Doctors often divide the breast into five zones, or quadrants, to help locate problems more precisely. Four quadrants surround the nipple, and a fifth central zone sits directly around the areola. This system helps your doctor describe where a lump, infection, or other issue is found.

What Is Breast Mastitis?

Breast mastitis is an inflammation of the breast tissue. It may or may not involve a true abscess, or pocket of pus. It most often affects women who are breastfeeding, but it can occur at any time.

Mastitis makes the breast feel hot, red, swollen, and very tender. Some women also develop a fever and feel generally unwell. In some cases, pus may drain from the nipple when the breast is pressed.

According to the Mayo Clinic’s overview of mastitis, the condition is most common during the first few weeks of breastfeeding. However, it can develop at other times too.

Epidemic Mastitis

Epidemic mastitis involves strains of bacteria — often penicillin-resistant Staphylococcus aureus — that spread through the act of breastfeeding. This type can spread quickly in hospital settings or maternity wards. When combined with other infections, it can become very serious.

The breast becomes extremely painful and red. Pus may appear at the nipple. Treatment includes antibiotics, warm compresses, and regular emptying of the breast.

Non-Epidemic Puerperal Mastitis

This type affects the connective tissue between the breast lobes. It most often develops when cracked nipples allow bacteria to enter the breast. Milk that is not fully drained from the breast also creates an environment where bacteria can grow.

Treatment involves antibiotics and making sure the breast is emptied regularly. Your doctor may recommend continuing to breastfeed or to pump milk to prevent further buildup.

Breast Abscess: When Infection Becomes Localized

A breast abscess is a collection of pus inside the breast tissue. It often develops when mastitis is not treated quickly enough. Abscesses can form in several locations within the breast.

The most common location is just below the areola, known as a subareolar abscess. Other locations include just under the skin, between the breast lobes, or behind the breast tissue itself. One classic sign is a yellow stain left on a cloth or pad when the nipple is gently pressed — this is a helpful early warning sign.

Common symptoms of a breast abscess include:

• Breast pain and tenderness
• Redness and warmth over the skin
• Swelling in one area of the breast
• Fever or general feeling of illness
• Swollen lymph nodes under the arm

For more detailed information on breast infections, Healthline’s guide to breast abscesses offers a helpful overview of symptoms and treatment options.

Chronic Breast Abscess

A chronic abscess develops when an acute mastitis infection does not fully heal. Over time, the area becomes hard and nodular. It may feel like a firm, painful lump under the skin.

Pressing the nipple may produce a purulent, or pus-like, discharge. A needle aspiration — where a doctor uses a small needle to draw out fluid — can confirm the diagnosis. Treatment usually involves repeated incisions to drain the pus, along with thorough cleaning of the area and a course of antibiotics. Severe or recurring cases may require surgical removal of the affected breast tissue.

Galactocele: A Milk-Filled Cyst

A galactocele is a benign cyst that forms in the breast and contains milk. It usually develops after a woman stops breastfeeding. The milk becomes trapped in a blocked duct and forms a smooth, movable lump.

Galactoceles are generally not painful and are not cancerous. However, they can become infected if bacteria enter the cyst. Your doctor can confirm the diagnosis with an ultrasound and, if needed, drain the cyst with a small needle.

Specific vs. Non-Specific Inflammatory Conditions

Inflammatory breast conditions can be either specific or non-specific. Non-specific inflammation is caused by common bacteria, such as Staphylococcus aureus or Streptococcus. These are the most common causes of breast mastitis and abscesses.

Specific inflammatory conditions are less common. They may be linked to underlying conditions such as tuberculosis or other systemic diseases. These require a more targeted treatment approach and further investigation by your doctor.

In addition, some inflammatory breast conditions can mimic the appearance of breast cancer. Therefore, any new lump, redness, or skin change in the breast should always be assessed by a healthcare provider promptly. Health Canada’s breast health resources provide further guidance on breast disease awareness for Canadians.

Breast Lymph Nodes and Why They Matter

The breast drains fluid through a network of lymph vessels. These vessels lead to lymph nodes, which are small glands that filter bacteria and other harmful substances. When the breast becomes infected, nearby lymph nodes often swell in response.

The main groups of lymph nodes related to the breast are found in the armpit (axillary nodes) and along the inside of the chest (internal mammary nodes). Swollen or tender nodes under the arm are often a sign that the body is fighting an infection in the breast. Your doctor will check these nodes during a physical examination.

When to See a Doctor

You should contact your family doctor or visit a walk-in clinic as soon as possible if you notice any of the following:

• A red, hot, or swollen area of the breast that does not improve within 24 hours
• A lump or hardened area that is painful to touch
• Pus or unusual discharge from the nipple
• Fever above 38.5°C alongside breast pain
• Swollen or tender lymph nodes under your arm

Most provincial health plans in Canada cover visits to your family doctor or a walk-in clinic for breast concerns. Do not wait to seek care. Early treatment of breast mastitis and abscesses prevents complications and leads to faster recovery. If you are breastfeeding and develop symptoms, your doctor can advise you on whether it is safe to continue nursing during treatment.

Remember, this article is for general information only. It is not a substitute for professional medical advice. Always consult your doctor or a qualified healthcare provider for diagnosis and treatment.

Frequently Asked Questions About Breast Mastitis

Key Takeaways

• Breast mastitis is an inflammation of the breast tissue, most common in breastfeeding women.
• Symptoms include breast pain, redness, warmth, swelling, and sometimes fever.
• A breast abscess is a localized pocket of pus that can develop when mastitis is left untreated.
• A galactocele is a benign milk-filled cyst that usually develops after stopping breastfeeding.
• Swollen lymph nodes under the arm often accompany a breast infection.
• Treatment typically includes antibiotics, warm compresses, and regular emptying of the breast.
• Always visit your family doctor or a walk-in clinic early if you notice signs of breast inflammation.
• Your provincial health plan covers assessment of breast concerns — do not delay seeking care.