Unsecured debt refers to any type of debt or general obligation that is not protected by a guarantor or collateralized by a lien on specific assets of the borrower in the case of bankruptcy or liquidation or failure to meet the terms for repayment. Unsecured debts are sometimes called signature debt or personal loans. These differ from secured debt such as a mortgage, which is backed by a piece of real estate. Unsecured loans are often sought out if additional capital is required although existing (but not necessarily all) assets have been pledged to secure prior debt. Because unsecured loans are considered riskier for the lender, they generally carry higher interest rates than collateralized loans. Examples of unsecured debt include credit cards, medical bills, utility bills, and other instances in which credit was given without any collateral requirement.