What does a lump or thickening in the breast or underarm indicate and what should I do about it?

Symptom Database

Have you ever noticed a lump or thickening in your breast or underarm? It can be a cause for concern, but it’s important not to panic. In this article, we will explore what a lump or thickening in the breast or underarm may indicate and what steps you should take if you notice one.

Understanding Breast and Underarm Lumps

A breast lump refers to an abnormal mass or swelling that can be felt in the breast tissue. Similarly, an underarm lump is a lump or swelling that occurs in the armpit area. Both breast and underarm lumps can vary in size, texture, and sensitivity.

Possible Symptoms of Breast and Underarm Lumps

While the presence of a lump or thickening is the primary symptom, there are other signs that may accompany it. These symptoms can include:

  • Redness or warmth in the affected area
  • Pain or tenderness
  • Changes in breast shape or size
  • Nipple discharge
  • Swelling in the armpit

Potential Causes of Breast and Underarm Lumps

There are several possible causes for breast and underarm lumps, including:

  • Fibrocystic changes: These are noncancerous changes in the breast tissue that can cause lumps or thickening.
  • Breast cysts: Fluid-filled sacs that can develop in the breast tissue.
  • Fibroadenomas: Benign tumors that commonly occur in young women.
  • Infections: Certain infections, such as mastitis, can lead to lumps or swelling in the breast or underarm.
  • Lipomas: Noncancerous fatty tumors that can develop in the breast or underarm area.
  • Breast cancer: While less common, a lump or thickening can be a sign of breast cancer. It’s important to note that most breast lumps are not cancerous.

Diagnosing Breast and Underarm Lumps

If you discover a lump or thickening in your breast or underarm, it’s crucial to seek medical attention for a proper diagnosis. Your healthcare provider may perform the following:

Physical Examination

Your doctor will examine the lump and the surrounding area, checking for any abnormalities or changes in the breast or underarm tissue.

Imaging Tests

Imaging tests, such as mammograms, ultrasounds, or MRIs, may be ordered to get a better view of the lump and determine its characteristics.


A biopsy involves removing a small sample of tissue from the lump for further examination. This procedure helps determine whether the lump is cancerous or benign.

Treatment and Prevention of Breast and Underarm Lumps

The treatment and prevention options for breast and underarm lumps depend on the underlying cause. Here are some common approaches:


If the lump is noncancerous, your doctor may recommend:

  • Monitoring: In some cases, your doctor may advise monitoring the lump over time to ensure it doesn’t change or grow.
  • Medication: Certain medications can help alleviate symptoms associated with breast or underarm lumps, such as pain or inflammation.
  • Drainage: If the lump is a cyst, your doctor may drain the fluid using a fine needle.
  • Surgery: In certain cases, surgical removal of the lump may be necessary, especially if it causes discomfort or poses a risk.


While not all breast and underarm lumps can be prevented, there are steps you can take to reduce your risk:

  • Perform regular breast self-exams to become familiar with your breast tissue and detect any changes early.
  • Attend routine mammograms as recommended by your healthcare provider.
  • Maintain a healthy lifestyle, including regular exercise and a balanced diet.
  • Limit alcohol consumption, as excessive alcohol intake has been linked to an increased risk of breast cancer.

Remember, it’s essential to consult a healthcare professional if you notice any changes or abnormalities in your breast or underarm. Early detection and prompt medical attention can significantly improve outcomes.


A lump or thickening in the breast or underarm can be a cause for concern, but it doesn’t always indicate something serious. Understanding the possible causes, symptoms, and appropriate steps to take is crucial for your overall health and well-being. By seeking medical attention and following the recommended treatment and prevention strategies, you can ensure the best possible outcome for your breast and underarm health.

Haroon Rashid, MD
Rate author
Urgent Care Center of Arlington, VA
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