Post-viral fatigue syndrome, more commonly called chronic fatigue syndrome, usually begins between the ages of 25 and 45 and is more prevalent in women than men. The disorder was officially defined by the U.S. Centers for Disease Control (CDC) in 1988, and they revised the definition in 1994. Post-viral fatigue syndrome is difficult to diagnose because fatigue is a symptom of many illnesses, but the CDC outlines definitive characteristics.
To be diagnosed with post-viral fatigue syndrome, a person must have experienced severe persistent or intermittent fatigue for at least four months, with no other medical condition determined as the cause. The chronic fatigue does not improve with rest and leads to a significant decrease in the person's work, educational, social and personal activity.
Other Definitive Symptoms
The individual must also have four or more specific symptoms from a list of eight. Two of these address specific characteristics of the fatigue. Sleep is unrefreshing, and physical or mental exertion can worsen symptoms for over 24 hours. Additional definitive symptoms include sore throat, enlarged and tender lymph nodes, muscle pain, non-inflammatory pain in multiple joints (pain without swelling or redness), headaches of a new type or severity, and problems with short-term memory or concentration.
People with post-viral fatigue syndrome often report feeling generally unwell. Some degree of fatigue is nearly always present, and may be at its worst when first waking. Physical activity can lead to exhaustion. They have chronic muscle and joint aches, headaches and sore throats. All these symptoms make them feel persistently lousy.
Other Possible Symptoms
A wide range of other symptoms are commonly reported by post-viral fatigue syndrome patients. These symptoms can include a chronic cough, dizziness, jaw pain, lightheadedness upon standing up, sensitivity to light and sound, night sweats, insomnia or sleeping many extra hours, restless-legs syndrome, depression and panic attacks. Additionally, these individuals may have gastrointestinal problems such as diarrhea and bloating and often are diagnosed with irritable bowel syndrome.
Researchers have not determined the cause of post-viral fatigue syndrome. The sore throat and enlarged lymph nodes symptoms point to the syndrome having a viral basis. Previously it was considered to result from chronic Epstein-Barr virus infection, but this theory is no longer in favor.