A growth in the breast that could look or feel different from the tissue around it.

If an infection called mastitis causes a breast lump that's painful while breastfeeding, it can help to change feeding positions. Extra fluids and rest also may help.

See a health care professional right away if a breast lump grows or happens with:

• Fever or chills.
• Breast tenderness, swelling or warmth.
• Pain or a burning feeling in the breast.

See a health care professional about any breast lump, especially if:

• The lump feels firm or fixed.
• It doesn't go away after 4 to 6 weeks.
• It changes in size or starts to feel different.
• An area of skin on the breast changes color, dimples or puckers.
• A nipple turns inward or releases unusual or bloody fluid.
• A lump in the armpit forms or seems to get bigger.