You do not need an attorney or disability representative to win your case BUT having an attorney does increase your odds of being awarded disability benefits. While an attorney is not a doctor, experienced disability attorneys have represented claimants with most medicals condition before, and they know what it takes to get benefits for each condition.
An attorney has the proper legal knowledge and expertise to assist you with your case as well as access to federal Social Security laws, prior Social Security rulings, and medical research tools that will increase your odds of winning at a hearing.
An attorney has the experience of knowing exactly what legal and medical research is needed to properly defend your case as well as knowing exactly what questions need to be to asked, what key documents or diagnostic tests need to be discussed, and what evidence certain judges look for during the court proceeding.
An attorney also has a vast number of resources to deal with the specific issues and medical conditions that you are claiming in your case, including being able to pay to send you for certain medical tests that Social Security won't pay for.
An attorney also knows how to deal with medical evidence that does not support your claim for disability (for instance, a doctor's opinion that you are not disabled or the results of an exercise stress test that seems to show your heart is working fine).
You may have a medical expert or vocational expert hired by Social Security to be present at your hearing who will be discussing the facts of your case. An attorney will know how to cross-examine those experts and make sure that the hired experts properly state the facts of your case.
Learn more about the medical records you need to win a disability claim, or contact a lawyer here.