What does it mean if there is a lump in the breast?

The appearance of a lump in the breast may be a sign of breast disease, with common causes including mammary hyperplasia and breast cysts. Mammary hyperplasia refers to the overgrowth of breast tissue, leading to nodules or lumps in the breast, which are mostly benign. Breast cysts are fluid-filled sacs that develop within the breast due to the proliferation of cyst-like structures, and these are also typically benign. Mastitis can also cause breast lumps, which are usually accompanied by significant tenderness, redness, and swelling of the local skin. Lumps caused by lactational mastitis are mostly due to milk stasis, whereas non-lactational mastitis may result from other factors. Therefore, it is recommended to seek medical evaluation and treatment at a hospital.