Large breasts can cause some serious issues over time, including back pain, poor posture, and troubles with breathing. Additionally, larger breasts have a tendency to sag more noticeably later in life. If you are struggling with large breasts and want to make a change, get started with Step 1 below to learn how to reduce your bust line. To reduce your bust, try wearing a minimizing bra or a firm sports bra to make your bust look smaller. Alternatively, wear clothes that accentuate your hips in order to make your bust look smaller by comparison.