Signs and Symptoms of Breast Cancer

This is the second article in the Understanding Breast Cancer Guide. This guide was developed by the HealthTree Education Team and was last updated and reviewed on May 18, 2026

Breast cancer is a type of cancer that affects the cells of the breast, causing them to grow and multiply too fast. This forms a tumor.

These changes cause the first signs and symptoms of breast cancer. "Signs" are things that can be measured by tests, like a lump found on imaging. "Symptoms" are things you feel in your body, like pain or nipple discharge.

It is important to know that many breast cancers, especially in early stages, do not cause any symptoms at all. This is why regular screening is so important. Many cancers are found through routine mammograms before any symptoms appear.

Remember: Many of the signs and symptoms listed below can be caused by conditions other than cancer, such as a benign cyst or fibrocystic breast changes. If you notice any changes to your health, talk to your doctor.

What are the signs and symptoms of breast cancer?

Changes in the breast or underarm area

• A new lump or mass in the breast or underarm (axilla). This is the most common symptom of breast cancer. The mass may feel hard, irregular, or painless. Some lumps are soft or tender.
• Swelling in part or all of the breast, even without a distinct lump.
• A lump or swelling in the underarm or around the collarbone. This is a sign that cancer may have reached the lymph nodes.

Skin changes on the breast

• Dimpling, puckering, or thickening of the skin on the breast.
• Redness, scaling, or flaking of the skin on the breast or nipple.
• Skin that looks like an orange peel. This is called peau d'orange. It can be associated with inflammatory breast cancer.

Nipple changes

• A nipple that has turned inward when it previously pointed outward. This is called nipple inversion.
• Nipple discharge, including clear, bloody, or other fluid that is not breast milk.
• Scaling, crusting, or peeling of the skin on the nipple.

Pain

• Pain in the breast or nipple, though breast cancer is more often painless.

Note: Most breast pain is not caused by cancer, but any persistent unexplained pain should be evaluated.

Unexplained changes in overall health

• Unexplained weight loss.
• Persistent fatigue or weakness.
• Bone pain. This is a possible sign of spread to the bones in advanced disease.

If you are experiencing any of the symptoms listed above, or notice any changes to your health that concern you, the most important thing you can do is talk to your doctor. 

Many of these symptoms have causes other than cancer, but getting checked is always the right step. And if you are not experiencing any symptoms, that is not a reason to skip screening. Finding breast cancer before symptoms appear gives you the best chance of successful treatment.