Retired Justice Sandra Day O'Connor made public her family's private battle with the mind-destroying illness Wednesday as she urged Congress to speed research in hopes of slowing a coming epidemic.

"Our nation is certainly ready to get deadly serious about this deadly disease," she told the Senate Special Committee on Aging.

She has a personal stake: "My beloved husband, John, suffers from Alzheimer's," she said, her voice briefly wobbling. "He's not in very good shape at present."

Her story resonated with senator after senator who told of mothers and fathers crippled and then killed by Alzheimer's inexorable march -- and with a crowd of about 300 onlookers, many wearing purple Alzheimer's Association sashes, who applauded the calls for aid in a Senate hearing room where such emotion is rare.

More than 5 million Americans are living with Alzheimer's disease. The number is poised to skyrocket, with 16 million people forecast to have it by 2050 thanks to a graying population. It already afflicts one in eight people 65 and older, and nearly one in two people over 85.

"I'm getting pretty close to 80, so that gets my attention," O'Connor said wryly. "I think a lot of people will be concerned."

And with that specter of disease comes a bigger question: Who will care for all these patients? Already, 10 million people are estimated to be sharing the overwhelming task of caring for a relative or friend with dementia, juggling jobs and other family responsibilities with little formal training, support or financial help available. The Alzheimer's Association says the unpaid care they provide is valued at $89 billion.

The intensely private O'Connor has said little until now of her personal experience. But it illustrates some of that balancing act: When her husband could no longer stay home alone, O'Connor would take him to work with her at the high court. She announced her retirement in 2005 by saying she needed time to care for him, and eventually moved him to an assisted care center in Phoenix, near two of their three children.

On Wednesday she urged better support for caregivers and repeatedly stressed the need to speed quality research, citing the possibility of such treatment approaches as attacking a brain-clogging gunk called beta-amyloid that is the disease's hallmark.

"What we have to ask is whether this rapid growth is inevitable," she said. "I think it's not -- if we can fund the research."