Laboratory Testing And Diagnosis For Chronic Fatigue Syndrome

Extreme fatigue that is ongoing and cannot be explained by a medical condition or has no other scientifically proven cause is called Chronic Fatigue Syndrome or CFS. Chronic Fatigue Syndrome can be detrimental to a person’s ability to perform and complete even the most basic daily or routine tasks and activities.

Even though a person is continuously fatigued, they have trouble sleeping and often wake to feel as if they have not slept at all.

Other symptoms that they may experience include:

  • Recurrent headaches
  • Pain in the joints and muscles
  • Frequent sore throat
  • Problems with memory, focus, and concentration

Not every person may experience all these symptoms and may be affected to varying degrees, which may change from day to day. In extreme cases, CFS can last for an extended period exceeding six months. A person may be able to function almost normally on days when the symptoms are mild but on bad days, may not be able to get out of bed at all. Resting and sleeping do not resolve chronic fatigue, and mental activity may increase the symptoms.

CFS can affect any person regardless of age, gender, ethnicity, or economic standing anywhere in the world. However, the disorder is estimated to be four times as prevalent in females than in males and in those between the ages of 40 and 50 years. The CDC (Centers for Disease Control and Prevention) has estimated that around 1 million people in the United States have CFS. However, only around 20% of these know that they have the disorder and have been formally diagnosed.

Currently, there is very little known about the cause of CFS. Although a single cause has not been identified, scientific research has revealed several different triggers that include the following:

  • Although no specific microbe has been attributed to the cause of CFS, viral infections like the Epstein Barr Virus may trigger the condition
  • Trauma, stress, or allergies that result in immune dysfunction may, in turn, trigger CFS
  • Malnourishment or nutritional deficiencies
  • Neurally mediated hypotension or extremely low blood pressure causing fainting may be a trigger
  • Disturbances in the hypothalamic-pituitary-adrenal (HPA) axis, which may result from inactivity, psychiatric comorbidity, extended stress, disturbances in sleep patterns, and medication
  • After studying familial CFS patterns, researchers believe that there may be a genetic component that would make certain people more predisposed to the disorder

Current research points to CFS being a group of disorders that all result in the same symptoms rather than a singular condition. However, more research is required for scientific confirmation.

A definitive group of onset symptoms has been identified by those who have been diagnosed with CFS. In other words, specific symptoms that they experienced during a time when they had the required energy to function and complete routine tasks. It has been concluded that around 75% of the time, CFS patients experience what appear to be flu-like symptoms. In other patients, CFS followed an extended or extreme period of mental or physical stress. The symptoms of CFS also develop slowly, resulting in a gradual decline in energy levels and overall wellbeing.

There are, however, several illnesses, diseases, and health conditions that may present with a similar set of symptoms and side effects but must be distinguished from CFS. These conditions are the underlying cause of chronic fatigue and may be short or long-term. Some diseases that may present with chronic fatigue but must exclude a diagnosis of CFS include:

  • Hypothyroidism or thyroid that is under-performing
  • Mononucleosis commonly called mono
  • Psychological disorders or mental health conditions
  • Eating disorders like anorexia or bulimia
  • Cancer and cancer treatments
  • Autoimmune diseases
  • Infection
  • Abuse or addiction to substances such as drugs and alcohol
  • Side effects or reactions to prescription medications
  • An inability to achieve enough uninterrupted sleep

Unfortunately, there is currently no single evaluation or test that can be used to diagnose CFS accurately. The signs and symptoms of the disorder are used as qualifying criteria to reach a diagnosis.

Signs And Symptoms Of CFS

On conjunction with a panel of international expert researchers, the CDC have established a definition for Chronic Fatigue Syndrome and a list of signs and symptoms that therefore define the disorder:

  • Severe chronic fatigue must last for a minimum period of 6 consecutive months or longer without any known medical conditions having been previously clinically diagnosed
  • The ability to perform basic or routine daily tasks must be severely affected

A minimum of four of the following eight symptoms must occur during the six-month period, either ongoing or on a recurring basis:

  • An inability to concentrate, shortened attention span, and impaired short-term memory
  • Frequent or persistent sore throat
  • Lymph nodes in the neck or armpits that are sore and tender
  • Pain in muscles
  • Multiple joint pain that is unaccompanied by inflammation (swelling) and/or redness
  • Unfamiliar headaches, more extreme or occurring in new patterns
  • Waking up feeling unrefreshed
  • Extreme fatigue that lasts more than 24 hours after mental or physical activity

The National Academy of Medicine Committee on Diagnostic Criteria for Myalgic Encephalomyelitis (Chronic Fatigue Syndrome) released additional diagnostic criteria in a report for CFS to improve on the existing criteria for diagnosis and care of those who are suffering from the health condition. Some of the criteria are similar or the same as those that have been outlined above. Additional criteria that medical practitioners can use to diagnose the ME or CFS accurately include:

  • Extreme fatigue must be new and be present for more than six months, defined by a specific beginning. It should not have been caused by excessive exercise and cannot be improved by resting. It must affect the ability to perform basic daily activities such as work, school personal hygiene to a certain degree.
  • It must negatively impact general wellbeing and present with a general feeling of malaise (illness), which is increased after expending energy

One of the following symptoms should also be present at least 50% of the time, and it must be determined how severe and how often they occur:

  • Cognitive Impairment resulting in an inability to concentrate for a period of time, a short attention span as well as problems with memory
  • Orthostatic Intolerance is feeling dizzy or light-headed or having heart palpitations when rising from a sitting or resting position that could result in faintness or fainting

The less common side effects and symptoms of CFS include:

  • Gastrointestinal conditions such as abdominal pain, bloating, loss of appetite, nausea, and/or vomiting
  • Sensitivity or an adverse reaction (allergic reaction) to certain foods, odors, sounds, medications, or chemicals
  • Night sweats or chills
  • Constant or consistent (chronic) coughing
  • Anxiety and/or depression
  • Frequent urination
  • Sensitivity to cold and heat
  • Lowered body temperature
  • Dry mouth and eyes
  • Earache
  • TMJ (Temporomandibular Joint) dysfunction or pain in the jaw
  • Mild fever
  • Stiff joints, particularly in the mornings
  • A sensation of numbness, tingling, or burning in the extremities (hands and feet) and the face
  • Shortness of breath

Tests For CFS

As there are currently no specific blood tests, imaging scans, or other means of an accurate diagnosis for chronic fatigue syndrome, diagnosis is one of exclusion. This means that all illnesses, disease, or other health conditions that may present with similar symptoms must be excluded before arriving at a diagnosis of CFS.

Diagnosis will, therefore, involve the following:

  • Detailed documentation of the medical history of a patient
  • A thorough medical examination
  • Performing cognitive function tests
  • Excluding any other conditions that may be causing or aggravating fatigue as well as providing treatment for those conditions that can be treated
  • Ensuring that the condition fulfills the criteria to meet the CDC definition and/or National Academy of Medicine criteria
  • Monitoring of a patient over a period of time to evaluate whether there may be any other underlying causes

Classification of idiopathic or unknown chronic fatigue will be made should the condition fail to meet the CDC definition or the National Academy of Medicine criteria or where the symptoms are not severe enough to warrant a diagnosis of CFS.

As there is currently no definitive test to diagnose CFS, laboratory testing is used to eliminate and provide treatment options for health conditions or disorders with similar symptoms. The CDC provides guidelines for the basic tests that should be performed, but these could be dependent on other symptoms as well as the health care practitioner managing the case.

Laboratory Tests For Exclusion Purposes

A Comprehensive Metabolic Panel (CMP) includes a variety of different tests to determine the health of organs and identify a range of health conditions such as kidney and liver disease.

A Complete Blood Count (CBC) evaluates blood disorders specifically to look for infection or anemia and other conditions.

C-reactive Protein or Erythrocyte Sedimentation rate, which acts as indicators of nonspecific inflammation in the body.

Thyroid Stimulating Hormone (TSH), including other types of thyroid testing for hypothyroidism.

Iron Studies to detect anemia or an iron deficiency.

Urinalysis to identify infections or other conditions.

Any additional tests that a medical practitioner deems necessary in identifying diseases or health conditions or excluding them as causes of the symptoms of CFS. These additional tests may include:

Antinuclear Bodies (ANA) to identify autoimmune disorders.

Lyme disease tests if the disease is suspected, and the geographical area gives cause for testing.

Rheumatoid Factor to detect Rheumatoid Arthritis.

HIV Antibody Test to identify or eliminate an HIV infection.

Cortisol Testineg to identify low concentrations of cortisol as well as adrenal gland function.