Breast swelling during pregnancy

Both breasts may feel heavier, tender or more sensitive, and veins or the areolae may become more noticeable. Symptoms should still be judged by their pattern and associated signs.

Pregnancy hormones increase blood flow and stimulate the milk-making structures inside the breast. This can create diffuse fullness in both breasts. Localised swelling may instead reflect a blocked skin gland, a cyst, inflammation or infection, while a persistent lump has other possible causes that require examination. General fluid retention usually affects other areas as well and should not be assumed to explain a new focal breast change.

Wear a supportive, correctly fitting bra without tight seams pressing on swollen tissue. A cool or warm compress may be used according to comfort, with a cloth protecting the skin. Avoid forceful massage or squeezing a lump. Notice whether swelling affects one breast or both, whether redness spreads, and whether a distinct area remains after general tenderness settles. Mention any persistent or unfamiliar change at an antenatal appointment.

Seek prompt medical advice for a new or persistent lump, swelling confined to one breast, redness, heat, severe pain, skin dimpling, bloody nipple discharge or a new change in nipple shape. Fever, chills, rapidly spreading redness or feeling very unwell needs urgent assessment. Sudden swelling of the face or hands, especially with severe headache, visual disturbance, pain beneath the ribs or feeling acutely unwell, can occur with pre-eclampsia and requires urgent maternity assessment.

Ask whether the change feels like normal pregnancy-related tissue or needs imaging, which imaging option is suitable during pregnancy, and which changes should trigger earlier review. Tell the clinician when it began, whether it is worsening and whether fever, discharge, headache or swelling elsewhere is present.