The evaluation of chronic fatigue syndrome begins with a medical history and physical exam.

In order to diagnose chronic fatigue syndrome, a person must have severe fatigue for more than six months, and have 4 of the following symptoms:

• Poor memory and concentration
• Sore throat
• Tender and swollen lymph nodes (generalized)
• Muscle pain
• Joint pain (multiple joints)
• Headache
• Difficulty sleeping
• Malaise
• Feelings of laziness that persist for at least 24 hours following physical or mental exertion

Physical findings in someone with chronic fatigue syndrome may include:

• Inflamed throat with tonsillitis
• Skin rash
• Swollen lymph nodes in the neck
• Swollen lymph nodes (generalized)
• Spleen enlargement
• Less common finding
• Mild tenderness over the liver:
• Common finding

There are no special tests available to confirm the diagnosis of chronic fatigue syndrome. The diagnosis is made after illnesses that cause similar symptoms have been excluded through testing.

Tests that may be used to evaluate chronic fatigue syndrome include:

• Monospot:
• Detects heterophil antibody to mononucleosis
• Complete blood count
• Peripheral blood smear
• Epstein-Barr virus specific serologic testing
• Throat culture
• excludes strep throat
• Liver profile
• May show mild elevations in liver enzymes