Fatigue can stem from a variety of illnesses and life stressors, but when that exhaustion lasts for months — often following an infection — it may indicate a condition called chronic fatigue syndrome.

We’re starting to get a handle on the role that genetics plays in the onset of chronic fatigue syndrome, or myalgic encephalomyelitis (ME/CFS). According to the largest study of its kind to date, more ...

A woman on an exercise bike performs a fitness test using a mask connected to a monitor, monitored by a professional. Chronic fatigue syndrome — medically unexplained fatigue lasting six months or ...

It’s normal to feel wiped out after a hectic week, a poor night’s sleep or a lingering cold. But for some people, exhaustion isn’t something that goes away after rest. It becomes a constant companion ...