Chronic Fatigue Syndrome, or Myalgic Encephalomyelitis (ME/CFS), is a debilitating disorder characterized by severe fatigue that does not improve with rest, alongside symptoms like muscle pain, memory issues, and sleep disturbances. The exact cause is unknown, but viral infections, immune dysfunction, and hormonal imbalances are potential triggers. Management involves pacing activities, cognitive-behavioral therapy, and symptom-relief medications. Research continues to uncover the underlying mechanisms and improve treatment approaches.