Why does premenstrual syndrome cause breast pain?

Before a period, shifts in oestrogen and progesterone can influence the milk-producing tissue and fluid balance in the breasts. This may create fullness, heaviness, aching, or sensitivity, often in both breasts and sometimes extending toward the armpits. The discomfort commonly changes with the menstrual cycle and eases as bleeding starts or shortly afterward. Cyclical tenderness is different from a new persistent lump or pain in one specific spot. Breast pain can also have other explanations, including pregnancy, a medication effect, an injury, or an infection, so the pattern matters.

A well-fitting supportive bra, including during exercise, may reduce movement-related discomfort. Warmth or a cool pack can be tried for short periods, with a cloth between the pack and skin. Gentle movement and recording symptoms across cycles can help you identify triggers and discuss suitable pain relief with a pharmacist or clinician. Do not stop prescribed medicines without advice.

Arrange a clinical assessment for a new lump, skin dimpling, nipple inversion, spontaneous nipple discharge, redness with fever, or pain that does not follow your usual cycle. Seek prompt care if the breast becomes hot, very swollen, or rapidly more painful. These signs need assessment because causes other than PMS may require treatment.

Ask whether your pain pattern is cyclical, whether any medicine could contribute, and which examination or imaging is appropriate for your symptoms. Bring your symptom diary and mention pregnancy possibility, breastfeeding, and family history.