Applying for Social Security Disability can seem daunting.  The general test requires applicants to establish that they cannot do ANY gainful employment in the national economy.
Carefully making your case, and thoughtfully filling out the application and providing supportive medical information from treating health care professionals is important.  Even so, many months, even a year or more, might pass, before you are approved (or denied). The mere fact you can’t do your current or immediate past job, isn’t usually enough to qualify. This is so even if you have some medical conditions or concerns that make life more difficult than before.
But two important provisions — found in Social Security law and regulation — makes the application process easier for  certain applicants who really need Social Security disability.
One provision is the Compassionate Allowances program.  Social Security has recognized some conditions or diseases as so nasty, or debilitating or fast acting, that few would disagree that the applicant’s disease or condition  meets Social Security’s statutory standard for disability.  Almost every year Social Security adds more conditions  to the list. In effect, if you or someone you care for, has one of the conditions listed, their application will be handled on a fast-track basis.
For more, on the Compassionate Allowances program see these Social Security webpages:
http://www.socialsecurity.gov/compassionateallowances/cal_faqs.htm
http://www.ssa.gov/compassionateallowances/conditions.htm
Another provision can make applications a bit easier for older workers.  Right or wrong, one might say that Social Security acts as though old dogs can’t learn new tricks.  Naturally they don’t put it that way. But in fact, older workers applying for Social Security disability will find that Social Security does look at age as a “vocational factor”.  See more here:
http://www.ssa.gov/OP_Home/cfr20/404/404-1563.htm
Social Security provides a general overview of the disability benefits and application process here:
http://www.socialsecurity.gov/pubs/EN-05-10029.pdf