Chronic fatigue syndrome, also known as CFS, is characterized by disabling symptoms such as extreme exhaustion or fatigue and trouble sleeping. As a result, many patients diagnosed with CFS also suffer from cognitive problems that can impair memory and cognitive functioning. While the symptoms are recognizable to most doctors, it remains unclear what actually causes chronic fatigue syndrome.It was not until the 1980s that the first noted cases of CFS were recording in the United States. To this day, doctors and researchers remain divided as to the believed cause for the syndrome. While some believe that CFS may be caused by viral infections, others are not so sure.Other researchers and doctors have more or less dismissed the condition and written it off as a stress-related problem or a psy