Q. In reading about Social Security, I sometimes see references to "compassionate allowances." What are these exactly?

A. Compassionate allowances are the basis of a system by which Social Security fast-tracks the disability applications of people whose medical conditions are so severe that they're sure to qualify for benefits.

See also: How to apply for disability.

Basically, an application is sped up if the person has any of the diseases and conditions that are on a compassionate-allowances list that Social Security maintains. Now numbering 165, these include various forms of cancer, brain injury, heart disease, and immune system and neurological disorders.

The special processing saves the applicant from waiting months or even years to obtain benefits under the Social Security Disability Insurance (SSDI) and Supplemental Security Income (SSI) programs.

As of this past July, Social Security's normal process was taking an average of about 2-1/2 months to reach an initial decision on a disability application. People who wanted a hearing before an administrative law judge, the third level of appeal, had to wait an average of about 11 months for the hearing.

On the compassionate-allowances track, an application can be processed "within days," Social Security says.

Social Security Commissioner Michael J. Astrue, who was appointed in 2007, has made a focus of trying to reduce the backlog of disability cases. To get the compassionate-allowances program rolling, he has held seven public hearings in four years about various medical conditions to try to determine which deserve to be on the list.

An Alzheimer's hearing included testimony from not only medical experts but also family members who recounted the difficulties they faced when their breadwinners developed Alzheimer's disease in their early 50s and were unable to work. Although the disease generally afflicts older people, the Alzheimer's Association estimates that about 200,000 Americans under the age of 65 have the disease.

Early-onset Alzheimer's disease and related dementias were added to the list in 2010. "Now, individuals who are dealing with the enormous challenges of Alzheimer's won't also have to endure the financial and emotional toll of a long disability decision process," commented Alzheimer's Association Chief Executive Harry Johns.

You may also like: Do you have a question about taking care of a loved one?

Stan Hinden, a former columnist for the Washington Post, wrote How to Retire Happy: The 12 Most Important Decisions You Must Make Before You Retire. Have a question for the Social Security Mailbox? Check out the archive. If you don't find your answer there, send a query.

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