If your application is denied, it's important that you appeal rather than giving up and starting over. When you win, Social Security often pays you a lump sum that covers the period from the date of your application, and sometimes earlier, to the date when you win. If you give up and start over again, you may lose some of that retroactive benefit.
It's also very important, if your application is denied, to get a lawyer. Lawyers who do Social Security disability appeals don't get paid unless they win, and the amount they are paid is the lesser of 25 percent of that retroactive lump sum or $6,000 (the amount changes every year to adjust for inflation). Because lawyers who handle Social Security appeals can be hired without coming up with cash up front, Advocacy for Patients does not do Social Security appeals -- we focus on doing the things you can't get anywhere else. If you don't know an attorney, you can call us and see if we have anybody on our referral list, or you can call the National Organization of Social Security Claimants' Representatives (NOSSCR) at 800-431-2804. They also have a great set of FAQs that we find very helpful: http://www.nosscr.org/faq.html
Although the percentage of people who win at the initial application stage is low, roughly half of the people who appeal win. So don't give up; get yourself a lawyer and appeal.
Finally, I think the best advice I have for people who are applying for Social Security disability is to keep a diary for a little while before you fill out the application and/or before your appeal hearing. It will help you gather your thoughts, be precise and detailed (how many times did you go to the bathroom during the period from 9 a.m. to 5 p.m. on average in a two week period?), and remember all the information you want to convey.
And don't be shy; if you have accidents, say so. There's a horrible court decision I read once that sticks with me. The judge said a patient with inflammatory bowel disease wasn't disabled because, although she said she needed to be near a bathroom all the time, she never said she'd soiled herself!