Lump on the side of the breast

The outer breast blends toward the armpit, where lymph nodes and breast tissue can both be felt. A blocked skin gland, cyst, muscle strain, rib or cartilage irritation, and benign breast changes are other possibilities. A breast lump is a common presentation of breast cancer, but feeling a lump does not establish its cause.

Pay attention to whether it is in the skin, moves under the fingers, follows an injury, or appears with nipple or skin changes. These observations help a clinician choose the right examination.

Make an appointment for a lump that is new, firm, fixed, enlarging, or still present after a cycle. Avoid tight clothing that rubs the area and avoid trying to drain or crush a skin lump. Write down its position relative to the nipple and armpit, tenderness, and any change in the other breast.

A clinician can examine both breasts and the armpits. If the nature of the lump is unclear, imaging or another test may be recommended.

Seek prompt care for a red or hot lump, fever, rapid enlargement, or significant pain. Arrange timely assessment for nipple inversion, bloody discharge, skin dimpling, a thickened skin texture, or swelling in the armpit. Severe chest pain, breathing difficulty, or collapse requires emergency help.

Ask whether the lump is in breast tissue, skin, or an armpit structure; whether imaging is indicated; how to monitor it safely; and which changes should bring you back sooner.