Stress has been linked to all sorts of serious health issues, from insomnia to high blood pressure, obesity and even heart disease. But it’s generally acknowledged that some stress can also be helpful, like when someone’s chasing a work deadline. But what if some level of stress can actually protect the body? A new study by researchers at the Case Western Reserve University School of Medicine, with findings published Sept. 26 in Proceedings of the National Academy of Sciences, suggests the immune system may benefit from a measure of stress.