Diagnosis of fatigue typically begins with a physician obtaining a detailed medical history and discussing the condition with the patient. Patients should also report any additional symptoms that make fatigue worse, such as:

• Nausea or vomiting
• Pain
• Constipation
• Diarrhea
• Shortness of breath
• Inability to keep liquids or food down
• General weakness

To accurately assess fatigue, physicians may ask patients to rate their fatigue on a scale of zero to 10, where a rating of 10 indicates maximum fatigue. Patients may be evaluated for contributing conditions, such as anemia or infections. Physicians evaluate factors such as:

• The pattern of fatigue (e.g., when it began, how long it has lasted, etc.)
• Current medications
• Sleep patterns
• Eating habits
• Daily activities

A physical examination may be performed after the medical history. During an evaluation for fatigue, physicians often focus on examining the heart, lymph nodes and thyroid gland. Blood tests and urine tests may be ordered to identify or rule out certain conditions.

People with long-lasting fatigue do not necessarily have chronic fatigue syndrome (CFS). Patients must meet two criteria to be diagnosed with CFS, according to the U.S. National Institutes of Health (NIH):

• Have severe, chronic fatigue for six months or more, with other known causes ruled out by clinical diagnosis
  
  
• Have four or more of the following symptoms for the previous six months or longer:
  
  
• • Substantially impaired concentration or short-term memory
    
  • Sore throat
    
  • Tenderness in the lymph nodes of the armpits or neck
    
  • Muscle pain
    
  • Multiple joint pains without swelling or redness
    
  • Headaches of a new type, pattern or severity
    
  • Sleep that does not refresh
    
  • Malaise after exertion