The exact cause of CFS is still unknown. Some studies suggest the condition is genetic meaning it is passed to you by other members of your family. Other theories suggest a viral infection, hormone imbalance, stress or depression or an accident or trauma may trigger CFS.

Since the symptoms of CFS are similar to many other conditions, it can be difficult to diagnose. Your GP may order tests to rule out these other conditions.

You may also be referred to a specialist consultant for further diagnosis and treatment.