Your likelihood of a successful claim is grounded on the facts that you are able to present. Detailed medical records are essential. A successful claim requires the claimant to prove that due to mental and/or physical impairment one is unable to engage in "substantial gainful activity" and that this state of affairs has continued or is expected to continue for a year or longer or anticipated to result in death.
Social Security has two ways of evaluating claims: "The Listings" and "The Grids". Both of these are detailed in the agency's regulations.
Essentially The Listings are a list of diseases and conditions with specific medical criteria which are considered severe enough to establish disability without the need to consider any factors other than the medical evidence. An impairment can be found equivalent to a listed impairment "if the medical findings are at least equal in severity and duration to the listed impairment."
The Grids are the method for evaluating those cases which cannot be determined on the medical evidence alone. It is a screening process that serves as a guide as to whether or not a claim should or should not be allowed. Essentially, the claimant for benefits has to show that the claimant is not engaged in substantial gainful activity, has a severe impairment that does not meet The Listings and cannot perform their past relevant work. If these facts are established, the remaining issue is a determination of ability to do other work.
The rules applied under the grids are extremely harsh for younger workers (under age 50). As the worker ages beyond age 50, the rules become less difficult to prove disability. Other factors that are considered under The Grids and its Rules are whether the claimant can sustain a certain level of physical exertion; has skilled work experience; has transferable skills; and the level of educational attainment including literacy and ability to communicate in English.
Social Security disability is a complex area of law. Consultation with a knowledgeable professional should be considered by anyone who seeks disability benefits.