Many mothers are running on empty when it comes to their mental and physical health, according to new research. Doctors say they see firsthand the toll life can take on moms. "That stress manifests in a lot of different ways. Chest pains, shortness of breath, palpitations," said Dr. Susan Cheng, a cardiologist at Cedars-Sinai Medical Center. She says mothers need a minute to themselves – which sounds like an easy thing, unless they are running a household and caring for kids.