The present invention relates to a breast pump operable to generate a negative pressure comprising a funnel (24) for receiving a breast of a user. The breast pump (24) has an insert (50 70) receivable in the funnel (24) having a deformable region (59a 59e) which forms a chamber between the insert (50 70) and the funnel (24) when the insert (50 70) is received in the funnel (24). A passageway (37) connecting the chamber to the source of negative pressure is formed in the funnel (24) so that during use the deformable region (59a 59e) is deformed and/or deflected relative to the breast of a user in response to a negative pressure in the chamber.
