Does breast cyst cause breast lump?

A breast cyst is a fluid-filled area within breast tissue. It may feel smooth, round, or movable and can become tender or more noticeable around hormonal changes. Some cysts are small and cause no symptoms, while others create a distinct area of fullness. Feeling a lump cannot confirm that it is a cyst; solid and fluid-filled changes can feel similar without an examination and imaging.

Book an appointment for a new, persistent, or changing lump. Note when you first felt it, whether it changes during your menstrual cycle, and whether there is pain or nipple discharge. A clinician may examine the breast and arrange ultrasound or other imaging. If a cyst is confirmed and it is uncomfortable or large, drainage may be discussed; many cysts can instead be monitored.

Seek prompt review for a lump that is growing, hard, fixed, or associated with skin dimpling, nipple inversion, unusual discharge, or enlarged nodes near the armpit. Fever, spreading redness, warmth, and severe tenderness can suggest infection and need timely medical attention. These features do not identify the cause by themselves.

Ask whether the lump has features of a fluid-filled cyst and what imaging is appropriate. Ask whether monitoring or drainage is suitable, what changes should bring you back sooner, and when the lump should be checked again.