Ultrasound may be your next step if you and your doctor have confirmed that there's some sort of unexplained lump in your breast. Maybe you can't feel it, but it shows up on your mammogram. Or maybe your mammogram looks normal, but you (or your doctor) know it's there. "I started calling it Lumpy," says Kim Heier, 42, of Simi Valley, Calif., about the mysterious form in her breast. "It seemed to help."
Ultrasound can tell if your lump is fluid or solid.