Credit scoring models usually take into account how much you owe compared to how much credit you have available, called your credit utilization rate or your balance-to-limit ratio. Basically it's the sum of all of your revolving debt (such as your credit card balances) divided by the total credit that is available to you (or the total of all your credit limits).
You're also entitled to a free credit report if you've been turned down for credit because of something on your credit report, if you're currently receiving government assistance, if you're unemployed and plan to look for a job soon, or if you think you've been a victim of credit card fraud or identity theft. Some states even have laws that let you get an additional free credit report each year. All these free credit reports should be ordered directly through the credit bureaus.