It may be hard to imagine Grandma unable to pay her bills or Grandpa being hounded by debt collectors. But for millions of Americans, this is the harsh reality of retirement.

Faced with a fixed income and constantly rising cost of living, many seniors now spend their “golden years” juggling bills and fending off debt collectors.

“If they get a phone call at 10 o’clock at night and the caller is harassing them for a debt, it can be very scary,” said Amy Nofziger with the AARP Foundation. “We know that it causes a lot of stress for seniors because some of these debt collectors can use foul language and other forms of harassment to try to collect the debt.”

Nofziger told NBC News that some people pay off debts just to stop the calls, even though they don’t believe they truly owe the money.

“Older Americans deserve to be treated with the respect and dignity they deserve.”

The Consumer Financial Protection Bureau (CFPB) recently reported that for older Americans, debt collection is the top complaint. About one out of three complaints submitted to the agency by seniors is about debt collection. The major complaints include being hounded for medical debts currently in dispute, attempts to collect the debts of deceased family members from their relatives, and illegal threats to garnish Social Security and other federal benefits.

Harassment endangers health

“Older Americans deserve to be treated with the respect and dignity they deserve,” said CFPB director Richard Cordray.

The CFPB report noted that some of the seniors who complained about debt collectors expressed concern that “the distress of being harassed by a debt collector aggravates existing medical conditions and thereby endangers their health.”

Cindy Sebrell, vice president of public affairs at ACA International (a national trade group for the credit and collection industry), says legitimate, professional debit collectors “are respectful in all conversations with consumers” and only try to collect debt that is justly-owed.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

“Attempting to knowingly collect a debt from the wrong consumer is not only problematic from a legal perspective, it is also economically inefficient for the debt collector – it is a waste of time and resources, leads to complaints that must be resolved, and could quite possibly lead to expensive litigation,” she wrote in a statement to NBC News. “Every legitimate debt collector would want to avoid that situation.”

But not every debt collector plays nice.

The Center for Responsible Lending (CRL), a non-profit advocacy group, sees a system where “profiteers” can take advantage of people in financial distress.

“American consumers are profoundly and negatively affected by wrongful debt collection tactics on a daily basis,” said CRL’s Lisa Stifler in a statement. “No one should be forced to deal with illegal collection activity, and debt collectors should not be allowed to exploit vulnerable seniors in order to make a profit.”

The calls just wouldn’t stop

Michael, a 77 year-old retiree who lives in the Seattle area (he asked that we not use his last name for privacy reasons) realized he could not pay his credit card bills after he stopped working. So he contacted the two card companies and made payment arrangements that he could handle. That worked for a while, but eventually, they turned it over to collection. The calls started immediately, he said.

“Initially, they were not that aggressive, but over time when I made it clear that I had to abide by the initial payment arrangements that I had made, they would not accept that,” Michael told NBC News. “And then they started to threaten garnishment of my fixed income. I knew that if that happened that I was going to be in a place of real jeopardy.”

Michael was getting as many as four calls a day. He says the collectors told him they were prepared to garnish his Social Security payments. A few threatened him with arrest. He was afraid to answer his phone.

“And these calls would come early in the morning and late at night, and it was always from the point of view of we’re going to get you, no matter what you do,” he recalled. “When you hear that again and again, it becomes a pretty unsettling experience to say the least. The sense of belligerence which they exercise pretty effectively can be very, very scary.”

Eventually, the pressure, stress and anxiety began to impact his day-to-day-life, so Michael contacted a lawyer and decided his only option was to file for bankruptcy protection.

'Judgment proof'

Bev Clark is a volunteer at Senior Services of Seattle/King County. She helps educate older adults about their rights regarding debt collection. Many of her clients are “judgment proof” – they don’t own a home and their only income, Social Security or government pension is exempt from collection. But she told NBC News, they usually don’t know that and the debt collector won’t tell them.

The CFPB has published a list of things seniors can do to protect themselves:

Protect their federal benefits: Seniors need to know that most federal benefits are protected in debt collection. Also, when they receive federal benefits by direct deposit to a checking account, the bank or credit union is required automatically to protect up to two months’ worth of these benefits. Benefits received on a government-issued prepaid card are usually protected, too.

Get more information to identify the debt: Older consumers report that collectors often reject or ignore their attempts to correct cases of mistaken identification.

Dispute inaccurate debts: Many seniors complain that they tell collectors they don’t owe the debt, don’t recognize it or believe the amount demanded is wrong.

Stop the harassment: One of the most common debt collection complaints the CPB receives from seniors is that that collectors use abusive language or overly-aggressive tactics to intimidate, aggravate or coerce them into making payments.

The CFPB advisory has sample letters that can be used to find out information about the claims being made, dispute the debt and request that a debt collector stops collection communications. If you are having a problem with a debt collector, you can file a complaint with the CFPB.

Herb Weisbaum is The ConsumerMan. Follow him on Facebook and Twitter or visit The ConsumerMan website.