Student loans are given extensive protection under the law, much more so than other debts that you may have such as debts from credit card spending, medical bills or unpaid personal loans. Among the protections given to student loan lenders are restrictions on when a student loan can be bankrupted.
Under the law in the US, if you have a student loan in default, you may not have that loan discharged in bankruptcy and you may not include it in a chapter 13 bankruptcy repayment plan except in a very limited array of circumstances. In order to have a student loan discharged, you must seek a hardship discharge and you must meet very stringent standards.
Essentially, the standards for having a student loan discharged through a hardship discharge require you to prove that paying your student loan back now or in the future would impose an undue hardship on you. In other words, paying back your student loan must be virtually impossible for you if you are going to maintain any reasonable standard of living. Showing you have a low salary and that your student loan is making it a bit hard for you isn't enough- you have to show that you cannot possibly make enough income now or in the future to pay back the loan. Usually, this is granted only if you become disabled permanently and unable to work, or if there is some other drastic circumstance preventing you from being able to pay.
If you are seeking a hardship discharge for your student loan, you should strongly consider speaking with a lawyer for help if you want to maximize your chances of being successful in this difficult endeavor.