What should you know about lump below breast?

The lower breast meets the chest wall and the fold beneath it. A blocked skin gland, an inflamed hair follicle, a cyst, or a tender area from friction can feel close to the surface. A firm structure deeper under the breast may involve muscle, cartilage, or a rib rather than the breast itself. Hormonal breast changes can also cause fullness or nodularity that varies during the menstrual cycle.

Notice whether the area is in the breast, in the skin crease, or fixed to the chest wall. Breast cancer can present as a lump, although many lumps have non-cancerous explanations; location alone cannot identify the cause.

Look at the skin without repeatedly pressing the area. Record when you first noticed it, whether it changes with your cycle or movement, and whether there is pain, warmth, discharge, or a visible skin change. Arrange an appointment if it remains, grows, feels hard or fixed, or cannot be clearly explained by a surface irritation.

A clinician may examine the breast, fold, and chest wall together. Depending on the findings, they may recommend imaging or a sample. Do not squeeze a skin lump, and choose a supportive bra if rubbing makes the area sore.

Seek prompt medical care for a new lump with redness and heat, fever, rapidly increasing swelling, bloody nipple discharge, skin dimpling, nipple inversion, or an ulcer. Seek urgent help for severe chest pain, breathlessness, faintness, or sudden marked swelling. These signs need assessment because infection, inflammation, or a chest problem may require timely treatment.

Ask: Does this feel like breast tissue, skin, muscle, cartilage, or a lymph node? What examination or imaging is appropriate? What changes should make me return sooner? Could my menstrual cycle, recent exercise, injury, or bra friction be contributing?