As much as I wish differently, age does play an important factor in your Social Security Disability case. It seems that the older you are, the more likely the Social Security Administration is willing to concede that you are disabled. This is apparent in Social Security's Medical Vocational Guidelines (a.k.a. the Grids).
The Social Security Administration breaks down age into three categories. If you are 18-49 years old you are considered a "younger individual." From 50-55 years old, you are defined as an "individual approaching advanced age." And if you are 55+ years old, you are considered an individual of "advanced age." Found here.
But this is not to say that you will not be found disabled because you are young or that you will automatically be found disabled because you are over 55 years of age. You can only be found disabled if you can prove that you are unable to work based on your impairments.
There are essentially two ways to be found disabled, under the SSA Listings or under the Medical Vocational Guidelines. In addition to the above, the combination of your impairments may prevent you from working. The Medical Vocational Guidelines really do not help younger individuals at all. Some help is offered for younger individuals in the SSA Listings but the listings are difficult to meet in most cases.
Even though age does play a factor, you cannot help your age, nor the fact that your health has stopped you from working. If you are unable to work because of your health, apply for Social Security Disability Benefits as soon as possible. Delay may cause you to lose benefits!