Q: I’m tired all the time and feel like I’ve got a permanent case of the flu. I can’t seem to concentrate, I forget things easily, and I feel confused. My doctor says I have chronic fatigue syndrome and has given me an off-work notice. Can I apply for Social Security disability if this becomes a permanent thing?

A: You may have chronic fatigue syndrome, but you may not win your disability claim. Officially, CFS is now a “potentially disabling illness,” the effects of which are judged on a case-by-case basis. If you want to claim disability benefits for chronic fatigue syndrome, you should:

• Document your illness, describing the onset date, the symptoms, and whether it is getting worse or better.

• Mention the symptoms to your doctor and make sure he or she fully documents the course of the illness with progress reports, clinical and laboratory tests, a medical history, treatment recommendations, the prescription of medications, and psychological evaluations.

• Make sure your doctor notes the effect of your illness on your capacity to work and your functional limitations.

Social Security’s instructions to health professionals when evaluating CFS cases for the purpose of proving disability are posted at http://www.socialsecurity.gov/disability/professionals/cfs-pub063.htm.