Holy Cross Hospital's health center in Aspen Hill, Maryland, is bracing for more business. The center treats the uninsured, and has been busy since it opened in 2012 with a waiting list of more than 400 people at its clinic. Now, as a result of the U.S. Affordable Care Act, it's mulling adding staff and hours in anticipation of next year's rush of newly-insured patients, many with chronic medical conditions that have gone untreated for years. Poorly controlled diabetes can cause stroke, kidney failure and blindness. Undiagnosed cancer can translate into complex end-of-life care, and untreated high blood pressure can lead to heart attacks.