"Early in the illness the PWC (Person with CFIDS) is likely to experience swollen lymph glands, frequent infections and illnesses, fever and chills, sore throat, depression, and persistent headaches and myalgias.  As time goes on, additional symptoms, especially neurological symptoms, may develop or become worse."

Running on Empty by Katrina Berne, Ph.D.

In many cases, it begins with the "flu" that just won't go away.  Additional symptoms which develop over time can include tinnitus, sore throat, equilibrium problems, irritability, weight gain, shortness of breath, lymph node tenderness, unusual headaches, tendency to become "overloaded" easily, periods of depression, memory loss, heart palpitations, and weight loss.  For a complete list of symptoms consult a doctor.  One that believes that CFIDS is real, preferably.

Now don't go running to the doctor because you think this might be you.  I hate people who ask me the symptoms, I tell them, and then they say "Oh that must be what I have too".