No, they're not. People with chronic fatigue syndrome are more than "just tired." They're suffering from an intense fatigue that doesn't go away. No matter how long they sleep, they don't wake up feeling refreshed.
Many people with chronic fatigue syndrome also have a lot of muscle pain and other flu-like symptoms, so, essentially, they feel as if they have the flu all of the time. Their immune systems also show signs that they're actively fighting an infection.
Many researchers suspect the cause of chronic fatigue syndrome is at least in part to a chronic viral infection that's hard to dectect or a "hit-and-run" virus that leaves the immune system permanently activated.
Other Chronic Fatigue Syndrome FAQs

