What should you know about sudden painful lump in breast?

Tender lumps can occur with hormonal breast changes, a blocked duct, a fluid-filled cyst, or inflammation. Infection may cause warmth, redness, swelling, and fever. The timing of pain in relation to your menstrual cycle, breastfeeding, or a recent injury can help a clinician understand the pattern.

Breast cancer can present with a breast lump, although pain and sudden onset do not determine the cause. A lump that feels fixed or hard, skin dimpling, nipple inversion, bloody discharge, or a change in breast shape needs medical review. Most breast changes are not cancer, but self-examination cannot confirm the diagnosis.

Note the exact location, size as you experience it, tenderness, skin changes, nipple discharge, and whether it changes during your cycle. Wear a supportive bra and avoid repeatedly pressing the area, which can increase soreness. If you are breastfeeding, mention feeding pattern and any difficulty emptying the breast.

Book an appointment for a new lump, especially if it remains after your next cycle, grows, or is associated with redness or discharge. Assessment may include a breast examination and imaging chosen for your age, symptoms, and pregnancy or breastfeeding status.

Seek same-day medical help for a painful red or hot breast with fever, rapidly increasing swelling, pus, or feeling very unwell. Arrange prompt assessment for a new lump with skin dimpling, nipple inversion, bloody discharge, or an enlarged lump in the armpit.

Could this be a cyst, infection, hormonal change, or another cause? What examination or imaging is appropriate? What signs should make me return sooner? If I am breastfeeding, could a blocked duct or mastitis be involved?