Chronic fatigue syndrome, perhaps more than any other disease, has a bad rap.
It makes you debilitatingly tired from normal tasks but no amount of rest can help.
There's no blood test or other easily read biomarkers, so many doctors are reluctant to diagnose the condition no matter how bad things get.
Scientists have finally shed some light on the condition, finding that your gut bacteria and inflammatory agents in the blood may have something to do with it.
In a study published this month in the journal Microbiome, Cornell University researchers looked at stool and blood samples of 48 people diagnosed with chronic fatigue syndrome (or more formally, myalgic encephalomyelitis) and at 39 healthy volunteers.