Credit cards have never been more popular - about 35 million people in the UK have one, according to industry figures. The annual percentage interest rate, or APR - including fees and charges - can range from 0% to more than 60%. But for people with an average credit history it is typically about 25%.
Panorama has also spoken to people who say their lenders nudged them towards taking on new debts, despite the fact they were struggling financially.
One man told us how his bank had increased his credit limit, even though he had racked up almost £7,000 of debt during a manic episode linked to bipolar disorder. Another man described how he is now selling his home, after becoming overwhelmed by credit card debt when work dried up and his marriage broke down.
The woman with a £10,000 debt, mother of five Amanda - who receives universal credit and has requested anonymity - went to a debt charity for help. It took years, but Amanda says she got on top of her debt.
She had signed up with credit-score provider Experian and, like many people, thought checking her credit score was a responsible thing to do.
"It was really useful. I'd get the monthly alert of the status of my financial affairs," she says.