Post-exertional malaise, or “payback,” is one of the key diagnostic criteria for myalic encephalomyelitis/chronic fatigue syndrome (ME/CFS). It is also one of the symptoms that is hardest for people who haven’t experienced the condition to understand.
I often think of it as being similar to a hangover, which is something I think most people have experienced. As a healthy person, one night you might go out and have too much to drink. During the night you generally feel fine, unless you take it too far, but the next day you experience payback in the form of a hangover. You will feel tired, nauseous, headachy and maybe feel generally unwell. For healthy people this will normally last a day, unless you’re very luck or unlucky.
With ME/CFS, any activity can cause this “hangover” or payback. For some people it might be simply getting out of bed to use the bathroom, or even just sitting up in bed. For others, it could be going for a short walk, doing cleaning, or seeing friends. Sometimes it can be caused by a bad night’s sleep, or emotional trauma. It’s not always easy to predict what will cause payback, and sometimes this can last days, weeks or even months.
