Democratic presidential candidate Bernie Sanders is proposing to wipe out an estimated $81 billion in past-due medical debt. Up to 80 million Americans could be impacted.

“People definitely need to have their debt either forgiven or negotiated lower, so they can afford it without a hardship,” said Craig Antico, the co-founder of RIP Medical Debt, which buys and forgives medical debt.

Two-thirds of people who file for bankruptcy each year blame their health-care costs, according to one study. “People are one illness or accident away from financial ruin in this country,” Antico said.

Sanders’ announcement on medical debt builds on his Medicare for All plan, and would likely be paid for with a tax on corporations based on their CEO compensation. In a recent town hall, a military veteran from Nevada told Sanders he was considering suicide due to his $139,000 in medical debt.

CNBC spoke to people about how they fell into medical debt and how it shapes their lives.

KATHLEEN HERZIG couldn’t walk 10 feet without becoming breathless. The 58-year-old blackjack dealer from Primm, Nevada, needed an aortic valve replacement in 2017 and wound end up staying in the hospital for over a month.

Herzig didn’t have health insurance through her job, and now she has over $600,000 in medical debt. “It’s horrible,” she said. “I’ve never been in debt.”

She said her only way out is bankruptcy, but, she said, “I can’t even afford to file at this point in time.” She earns around $8 an hour, before tips. She’s also worried that having a bankruptcy on her record would make it hard to get a higher-paying job.

In the meantime, she’s harassed by debt collectors and has become depressed, she said. She still doesn’t have health insurance, and said she knows she should be going to a cardiologist but doesn’t want to go deeper into debt.

“There’s no way I can get that done,” she said. “I’m jeopardizing

DIANE DENTON’S husband, Don, woke up one morning in 2008 with a smashing headache that wouldn’t go away.

The Bolivar, Missouri, resident was diagnosed with viral meningitis and spent more than 75 days in different hospitals. He had two brain surgeries. The history and religious studies professor was out of work for more than a year. “We were devastated financially,” Denton, 60, said. “Our medical bills were 2 feet high.”

Even with health insurance, the family was forced to take on more than $30,000 in medical debt, a balance they’ll never be able to pay, she said. That’s in large part because of their ongoing health expenses: Like many American households, they spend more than $20,000 a year on premiums and co-pays.

And the couple directs around $200 toward their arrears each month. “We can’t afford to save for college,” Denton said. “We can’t put money away for retirement. My husband’s car is 25 years old.”

If they could get a fresh start financially, Denton said:“We’d be able to breath deeper.”

“For the first time,” she added, “we could put aside a little money for old age.”

STEVE AQUINO had always been healthy. The York, Pennsylvania, resident wasn’t too worried, then, when one evening his right foot began to really hurt. Then other areas of his body - his shoulders, neck and back - began to really hurt, too. Soon he could barely turn his head. Even walking was hard. “It felt like someone was sticking a knife between my vertebrae and then twisting it,” Aquino, 31, said.

The software developer eventually lost his job, and had to go on disability insurance. Five years later, he still doesn’t have a diagnosis. What he does have: thousands of dollars in medical debt from the flurry of tests and treatments he’s needed.

“I’ve been slammed with bills,” he said. He’s around $2,500 in the red, he said, and expects to rack up only more debt. “It’s getting harder and harder to do normal things,” he said. He has health insurance though his remote job, but his out-of-pocket expenses are still high. “It’s just really depressing.”

Freed from his existing medical debt, he said, he’d have more money to put toward his wife and two young children. “We don’t have any savings,” he said.

And he’d have more money to direct toward his health. Currently, he said, the debt deters him from seeking further medical tests. For example, he wants to get a full-body MRI because it could help crack the mystery that has derailed his life, but it could also cost him thousands of dollars.